Presentation of Anatomical Variations Using the Aurasma Mobile App

PubMed Central

Bézard, Georg; Lozanoff, Beth K; Labrash, Steven; Lozanoff, Scott

2015-01-01

Knowledge of anatomical variations is critical to avoid clinical complications and it enables an understanding of morphogenetic mechanisms. Depictions are comprised of photographs or illustrations often limiting appreciation of three-dimensional (3D) spatial relationships. The purpose of this study is to describe an approach for presenting anatomical variations utilizing video clips emphasizing 3D anatomical relationships delivered on personal electronic devices. An aberrant right subclavian artery (ARSA) was an incidental finding in a routine dissection of an 89-year-old man cadaver during a medical student instructional laboratory. The specimen was photographed and physical measurements were recorded. Three-dimensional models were lofted and rendered with Maya software and converted as Quicktime animations. Photographs of the first frame of the animations were recorded and registered with Aurasma Mobile App software (www.aurasma.com). Resulting animations were viewed on mobile devices. The ARSA model can be manipulated on the mobile device enabling the student to view and appreciate spatial relationships. Model elements can be de-constructed to provide even greater spatial resolution of anatomical relationships. Animations provide a useful approach for visualizing anatomical variations. Future work will be directed at creating a library of variants and underlying mechanism of formation for presentation through the Aurasma application. PMID:26793410

Anatomic variation of depth-dependent mechanical properties in neonatal bovine articular cartilage.

PubMed

Silverberg, Jesse L; Dillavou, Sam; Bonassar, Lawrence; Cohen, Itai

2013-05-01

Articular cartilage has well known depth-dependent structure and has recently been shown to have similarly non-uniform depth-dependent mechanical properties. Here, we study anatomic variation of the depth-dependent shear modulus and energy dissipation rate in neonatal bovine knees. The regions we specifically focus on are the patellofemoral groove, trochlea, femoral condyle, and tibial plateau. In every sample, we find a highly compliant region within the first 500 µm of tissue measured from the articular surface, where the local shear modulus is reduced by up to two orders of magnitude. Comparing measurements taken from different anatomic sites, we find statistically significant differences localized within the first 50 µm. Histological images reveal these anatomic variations are associated with differences in collagen density and fiber organization. Copyright © 2012 Orthopaedic Research Society.

Aberrant Anatomical Variation of Maxillary Sinus Mimicking Periapical Cyst: A Report of Two Cases and Role of CBCT in Diagnosis

PubMed Central

Sekerci, Ahmet Ercan; Sisman, Yildiray; Etoz, Meryem; Bulut, Duygu Goller

2013-01-01

Most periapical lesions are associated with microorganisms from infected root canal systems. Maxillary sinus can pose a diagnostic dilemma radiographically because of its anatomical variation which can mimic a periapical pathosis. The aim of this study was to describe two cases of aberrant anatomical variation of the maxillary sinus that presented radiographic similarities to a periapical cyst in order to call the attention of clinicians to the fact that several different diseases are able to mimic endodontic periapical lesions. An accurate assessment of this morphology was made with the help of cone-beam computed tomography (CBCT). PMID:23710374

[Efficacy of fusion image for the preoperative assessment of anatomical variation of the anterior choroidal artery].

PubMed

Aoki, Yasuko; Endo, Hidenori; Niizuma, Kuniyasu; Inoue, Takashi; Shimizu, Hiroaki; Tominaga, Teiji

2013-12-01

We report two cases with internal carotid artery(ICA)aneurysms, in which fusion image effectively indicated the anatomical variations of the anterior choroidal artery (AchoA). Fusion image was obtained using fusion application software (Integrated Registration, Advantage Workstation VS4, GE Healthcare). When the artery passed through the choroidal fissure, it was diagnosed as AchoA. Case 1 had an aneurysm at the left ICA. Left internal carotid angiography (ICAG) showed that an artery arising from the aneurysmal neck supplied the medial occipital lobe. Fusion image showed that this artery had a branch passing through the choroidal fissure, which was diagnosed as hyperplastic AchoA. Case 2 had an aneurysm at the supraclinoid segment of the right ICA. AchoA or posterior communicating artery (PcomA) were not detected by the right ICAG. Fusion image obtained from 3D vertebral angiography (VAG) and MRI showed that the right AchoA arose from the right PcomA. Fusion image obtained from the right ICAG and the left VAG suggested that the aneurysm was located on the ICA where the PcomA regressed. Fusion image is an effective tool for assessing anatomical variations of AchoA. The present method is simple and quick for obtaining a fusion image that can be used in a real-time clinical setting.

The Main Anatomical Variations of the Pancreatic Duct System: Review of the Literature and Its Importance in Surgical Practice.

PubMed

Dimitriou, Ioannis; Katsourakis, Anastasios; Nikolaidou, Eirini; Noussios, George

2018-05-01

Anatomical variations or anomalies of the pancreatic ducts are important in the planning and performance of endoscopic retrograde cholangiopancreatography (ERCP) and surgical procedures of the pancreas. Normal pancreatic duct anatomy occurs in approximately 94.3% of cases, and multiple variations have been described for the remaining 5.7%. The purpose of this study was to review the literature on the pancreatic duct anatomy and to underline its importance in daily invasive endoscopic and surgical practice. Two main databases were searched for suitable articles published from 2000 to 2017, and results concerning more than 8,200 patients were included in the review. The most common anatomical variation was that of pancreas divisum, which appeared in approximately 4.5% of cases.

An unusual case of Y-shaped right renal vein.

PubMed

Lavy, M; Martin, L; Eouzan, D; Turco, C; Heyd, B; Mantion, G; Parratte, B; Tatu, L

2015-01-01

Vascular renal anomalies are frequent, multiple and well described and result from errors in vessel embryogenesis between the 6th and 10th week of gestation. Historically, variations are described in anatomic dissection and currently mostly in image interpretation. We report an anatomic variation concerning the right renal vein which, to our knowledge, has never been described in the literature either by dissection or by radiological examination. This variation was discovered during the routine dissection of an embalmed male body. It consists of a Y-shaped right renal vein and is associated with multiple retroperitoneal variations: a bilateral accessory renal artery, a trident ending of the right renal artery and a left testicular vein variation. Venous and arterial renal anatomy and its variations are fundamentally important in renal surgery, especially concerning living donor renal grafts. These variations may be diagnosed thanks to injected tomodensitometry which has a good sensitivity and specificity for anomalies. Preoperative diagnosis of an anatomic vascular renal variation may reduce morbidity during surgery, which is why precise examination of injected tomography should be mandatory.

Scrotal antegradesclerotherapy demonstrates anatomical variations on venous drainage in paediatric, adolescent and young adult varicoceles.

PubMed

Wong, Y S; Chung, K L Y; Lo, K W Y; Liu, C S W; Fan, T W; Tse, S K S; Tang, P M Y; Chao, N S Y; Liu, K K W; Leung, M W Y

2014-01-01

Anatomical variations on venous drainage in varicoceles are under-reported. We report our experience in scrotal antegrade sclerotherapy (SAS) for adolescent varicoceles. Since 2011, 15 consecutive boys with left varicoceles were recruited. Under general anaesthesia, a 5-mm transverse incision was made at scrotal neck, testicular vein was cannulated at pampiniform plexus with venogram performed. Foam sclerosant by mixing sodium tetradecyl sulphate (STS), Lipiodol(®) and air was slowly injected under fluoroscopy. Postoperatively the patients were followed-up for varicocele grading, testicular size, and complications. Median age at operation was 14 (10-19) years. 80 % had grade three varicoceles, 33.3 % had smaller left testis before operation. Intra-operative venogram showed three different anatomical variations. Group I: eleven patients (73.3 %) had single distinct internal spermatic vein; Group II: two patients demonstrated duplication of internal spermatic vein draining into left renal vein; Group III: two patients had pampiniform plexus draining to iliac and/or paraspinal veins. SAS was performed in Group I and II patients. Sclerosant volume injected ranged from 1.5 to 4.5 ml. In Group III patients, surgical ligation of testicular veins was performed rather than SAS to avoid uncontrolled systemic sclerosant spillage. Mean length of stay was 1.13 day. One patient with scrotal haematoma and one other with minor wound dehiscence were managed conservatively. Mean follow-up period was 10.9 (1-22) months. Thirteen patients (86.7 %) achieved varicocele grading ≤ 1. There was no postoperative testicular atrophy, hydrocele and epididymo-orchitis. Scrotal antegrade sclerotherapy using STS foam is a safe and effective treatment for adolescent varicoceles. Anatomical variations on venous drainage in varicoceles are common.

Anatomical variations of uncinate process observed in chronic sinusitis.

PubMed

Tuli, Isha Preet; Sengupta, Subhabrata; Munjal, Sudeep; Kesari, Santosh Prasad; Chakraborty, Suvamoy

2013-04-01

Chronic Sinusitis, an extremely persistent illness, is surgically best treated by Functional Endoscopic Sinus Surgery. The ostiomeatal complex is the main area targeted and within it uncinate process is the first anatomical structure encountered. The significance of anatomical variations concerning age and sex of uncinate process in chronic sinusitis were evaluated. A prospective study on 50 patients of chronic sinusitis (100 uncinate processes) was done. The results were tabulated and analyzed using Statistical Package for Social Science (SPSS) 16.0. Type I superior attachment of uncinate process (67 %) was the most common variety in all ages and both sexes and a statistically significant relationship between Type I superior attachment of uncinate process and sex was found (p < 0.05). The typical uncinate process was most common (70 %) followed by medial deviation of the uncinate (24 %). This difference in occurrence was significant with respect to both age and sex (p < 0.05). Anatomical variations of uncinate process are not responsible for causing chronic sinusitis. Mere presence of these variations of uncinate is not an indication for FESS.

Multiple variations of the tendons of the anatomical snuffbox.

PubMed

Thwin, San San; Fazlin, Fazlin; Than, Myo

2014-01-01

Multiple tendons of the abductor pollicis longus (APL) in the anatomical snuffbox of the wrist can lead to the development of de Quervain's syndrome, which is caused by stenosing tenosynovitis. A cadaveric study was performed to establish the variations present in the tendons of the anatomical snuffbox in a Malaysian population, in the hope that this knowledge would aid clinical investigation and surgical treatment of de Quervain's tenosynovitis. Routine dissection of ten upper limbs was performed to determine the variations in the tendons of the anatomical snuffbox of the wrist. In all the dissected upper limbs, the APL tendon of the first extensor compartment was found to have several (3-14) tendon slips. The insertion of the APL tendon slips in all upper limbs were at the base of the first metacarpal bone, trapezium and fascia of the opponens pollicis muscle; however, in seven specimens, they were also found to be attached to the fleshy belly of the abductor pollicis brevis muscle. In two specimens, double tendons of the extensor pollicis longus located in the third extensor compartment were inserted into the capsule of the proximal interphalangeal joints before being joined to the extensor expansion. In two other specimens, the first extensor compartment had two osseofibrous tunnels divided by a septum that separated the APL tendon from the extensor pollicis brevis tendon. Multiple variations were found in the anatomical snuffbox region of the dissected upper limbs. Knowledge of these variations would be useful in interventional radiology and orthopaedic surgery.

Anatomical influences on internally coupled ears in reptiles.

PubMed

Young, Bruce A

2016-10-01

Many reptiles, and other vertebrates, have internally coupled ears in which a patent anatomical connection allows pressure waves generated by the displacement of one tympanic membrane to propagate (internally) through the head and, ultimately, influence the displacement of the contralateral tympanic membrane. The pattern of tympanic displacement caused by this internal coupling can give rise to novel sensory cues. The auditory mechanics of reptiles exhibit more anatomical variation than in any other vertebrate group. This variation includes structural features such as diverticula and septa, as well as coverings of the tympanic membrane. Many of these anatomical features would likely influence the functional significance of the internal coupling between the tympanic membranes. Several of the anatomical components of the reptilian internally coupled ear are under active motor control, suggesting that in some reptiles the auditory system may be more dynamic than previously recognized.

Patterns of Individual Variation in Visual Pathway Structure and Function in the Sighted and Blind

PubMed Central

Datta, Ritobrato; Benson, Noah C.; Prasad, Sashank; Jacobson, Samuel G.; Cideciyan, Artur V.; Bridge, Holly; Watkins, Kate E.; Butt, Omar H.; Dain, Aleksandra S.; Brandes, Lauren; Gennatas, Efstathios D.

2016-01-01

Many structural and functional brain alterations accompany blindness, with substantial individual variation in these effects. In normally sighted people, there is correlated individual variation in some visual pathway structures. Here we examined if the changes in brain anatomy produced by blindness alter the patterns of anatomical variation found in the sighted. We derived eight measures of central visual pathway anatomy from a structural image of the brain from 59 sighted and 53 blind people. These measures showed highly significant differences in mean size between the sighted and blind cohorts. When we examined the measurements across individuals within each group we found three clusters of correlated variation, with V1 surface area and pericalcarine volume linked, and independent of the thickness of V1 cortex. These two clusters were in turn relatively independent of the volumes of the optic chiasm and lateral geniculate nucleus. This same pattern of variation in visual pathway anatomy was found in the sighted and the blind. Anatomical changes within these clusters were graded by the timing of onset of blindness, with those subjects with a post-natal onset of blindness having alterations in brain anatomy that were intermediate to those seen in the sighted and congenitally blind. Many of the blind and sighted subjects also contributed functional MRI measures of cross-modal responses within visual cortex, and a diffusion tensor imaging measure of fractional anisotropy within the optic radiations and the splenium of the corpus callosum. We again found group differences between the blind and sighted in these measures. The previously identified clusters of anatomical variation were also found to be differentially related to these additional measures: across subjects, V1 cortical thickness was related to cross-modal activation, and the volume of the optic chiasm and lateral geniculate was related to fractional anisotropy in the visual pathway. Our findings show that several of the structural and functional effects of blindness may be reduced to a smaller set of dimensions. It also seems that the changes in the brain that accompany blindness are on a continuum with normal variation found in the sighted. PMID:27812129

Investigation of topographical anatomy of Broca's area: an anatomic cadaveric study.

PubMed

Eser Ocak, Pınar; Kocaelı, Hasan

2017-04-01

The sulci constituting the structure of the pars triangularis and opercularis, considered as 'Broca's area', present wide anatomical and morphological variations between different hemispheres. The boundaries are described differently from one another in various studies. The aim of this study was to explore the topographical anatomy, confirm the morphological asymmetry and highlight anatomical variations in Broca's area. This study was performed with 100 hemispheres to investigate the presence, continuity, patterns and connections of the sulcal structures that constitute the morphological asymmetry of Broca's area. Considerable individual anatomical and morphological variations between the inferior frontal gyrus and related sulcal structures were detected. Rare bilateralism findings supported the morphological asymmetry. The inferior frontal sulcus was identified as a single segment in 54 % of the right and two separate segments in 52 % of the left hemispheres, which was the most common pattern. The diagonal sulcus was present in 48 % of the right and 54 % of the left hemispheres. It was most frequently connected to the ascending ramus on both sides. A 'V' shape was observed in 42.5 % of the right hemispheres and a 'Y' shape in 38.3 % of the left hemispheres, which was the most common shape of the pars triangularis. Moreover, the full results are specified in detail. Knowledge of the anatomical variations in this region is indispensable for understanding the functional structure and performing safe surgery. However, most previously published studies have aimed to determine the anatomical asymmetry of the motor speech area without illuminating the topographical anatomy encountered during surgery.

Anatomic variations of the branches of the aortic arch in a Peruvian population.

PubMed

Huapaya, Julio Arturo; Chávez-Trujillo, Kristhy; Trelles, Miguel; Dueñas Carbajal, Roy; Ferrandiz Espadin, Renato

2015-07-31

Previous publications from two countries in South America found one anatomical variation not previously reported in the rest of the world, which in turn give some clues with regard to a racial difference. The objective of the present study is to describe variations in the anatomical distribution of the branches of the aortic arch in a Peruvian population. To describe variations in the anatomical distribution of the branches of the aortic arch in a Peruvian population. A descriptive study of patients who underwent a tomography angiography of the aorta was performed. We analyzed the reports that showed the description of the variations of the branches of the aortic arch based on the eight types currently described in the literature. From 361 analyzed reports, 282 patients (78.12%) had a normal aortic arch configuration (type I; aortic arch gives rise to the brachiocephalic trunk, left common carotid and left subclavian arteries); followed by type II (left common carotid artery as a branch of the aorta) with 41 patients (11.36%); and type IX (common ostium for the brachiocephalic trunk and the left common carotid artery) with 25 patients (6.93%). The latter and two other types are new variations. Aortic Arch Type I, Type II and Type IX were the most frequent variations in this Peruvian study. Additionally, we also found two more new types that have not been previously described in the literature. Further investigation regarding these variations is needed in order to assess a racial factor in South America and possible relationships with clinical or surgical events.

Variations in paranasal sinus anatomy: implications for the pathophysiology of chronic rhinosinusitis and safety of endoscopic sinus surgery.

PubMed

Nouraei, S A R; Elisay, A R; Dimarco, A; Abdi, R; Majidi, H; Madani, S A; Andrews, P J

2009-02-01

To study the radiologic anatomy of the paranasal sinuses in patients with and without chronic rhinosinusitis to assess whether anatomic variations are associated with disease pathology, and to identify those variants that may impact operative safety. Tertiary referral otolaryngology unit. Incidence and nature of anatomic variants with potential impact on operative safety, and the presence or absence of sinus mucosal disease and its correlation with anatomic variants with a potential impact on mucociliary clearance. We reviewed 278 computed tomographic scans from patients with rhinosinusitis symptoms to investigate anatomic variations that may predispose to sinusitis or impact on operative safety. The incidence of variants with potential impact on sinus drainage was compared between patients with and without sinus mucosal disease with logistic regression. A closed osteomeatal complex was identified in 148 patients (53%), followed by concha bullosa in 98 patients (35%). Closed osteomeatal complex and nasal polyposis were independent risk factors for sinus mucosal disease. Anatomic variants with a potential impact on operative safety included anterior clinoid process pneumatization (18%), infraorbital ethmoid cell (12%), sphenomaxillary plate (11%), and supraorbital recess (6%). In 92% of patients, the level difference between the roof of the ethmoid cavity and the cribriform plate was Keros I. Bony anatomic variants do not increase the risk of sinus mucosal disease. However, anatomic variants with a potential impact on operative safety occur frequently and need to be specifically sought as part of preoperative evaluation.

Calot's triangle.

PubMed

Abdalla, Sala; Pierre, Sacha; Ellis, Harold

2013-05-01

Calot's triangle is an anatomical landmark of special value in cholecystectomy. First described by Jean-François Calot as an "isosceles" triangle in his doctoral thesis in 1891, this anatomical space requires careful dissection before the ligation and division of the cystic artery and cystic duct during cholecystectomy. The modern definition of the boundaries of Calot's triangle varies from Calot's original description, although the exact timing of this change is not entirely clear. The structures within Calot's triangle and their anatomical relationships can present the surgeon with difficulties, particularly when anatomical variations are encountered. Sound knowledge of the normal anatomy of the extrahepatic biliary tract and vasculature, as well as understanding of congenital variation, is thus essential in the prevention of iatrogenic injury. The authors describe the normal anatomy of Calot's triangle and common anatomical anomalies. The incidence of structural injury is discussed, and new techniques in surgery for enhancing the visualisation of Calot's triangle are reviewed. © . Copyright © 2012 Wiley Periodicals, Inc.

Variations of the sciatic nerve anatomy and blood supply in the gluteal region: a review of the literature.

PubMed

Kanawati, Andrew James

2014-11-01

Variations of the sciatic nerve anatomy and blood supply are complex and largely not dealt with in common anatomy texts. Variations of the sciatic nerve anatomy can be divided into the height of division of its branches, relation of the branches to the piriformis muscle, and its blood supply. These variations should be well known to any surgeon operating in this anatomical region. It is unknown whether these variations increase the risk of surgical injury and consequent morbidity. This paper will review the current knowledge regarding anatomical variations of the sciatic nerve and its blood supply. © 2014 Royal Australasian College of Surgeons.

Multiple variations of the tendons of the anatomical snuffbox

PubMed Central

Thwin, San San; Zaini, Fazlin; Than, Myo

2014-01-01

INTRODUCTION Multiple tendons of the abductor pollicis longus (APL) in the anatomical snuffbox of the wrist can lead to the development of de Quervain's syndrome, which is caused by stenosing tenosynovitis. A cadaveric study was performed to establish the variations present in the tendons of the anatomical snuffbox in a Malaysian population, in the hope that this knowledge would aid clinical investigation and surgical treatment of de Quervain's tenosynovitis. METHODS Routine dissection of ten upper limbs was performed to determine the variations in the tendons of the anatomical snuffbox of the wrist. RESULTS In all the dissected upper limbs, the APL tendon of the first extensor compartment was found to have several (3–14) tendon slips. The insertion of the APL tendon slips in all upper limbs were at the base of the first metacarpal bone, trapezium and fascia of the opponens pollicis muscle; however, in seven specimens, they were also found to be attached to the fleshy belly of the abductor pollicis brevis muscle. In two specimens, double tendons of the extensor pollicis longus located in the third extensor compartment were inserted into the capsule of the proximal interphalangeal joints before being joined to the extensor expansion. In two other specimens, the first extensor compartment had two osseofibrous tunnels divided by a septum that separated the APL tendon from the extensor pollicis brevis tendon. CONCLUSION Multiple variations were found in the anatomical snuffbox region of the dissected upper limbs. Knowledge of these variations would be useful in interventional radiology and orthopaedic surgery. PMID:24452976

Bilateral subclavian origin of the bronchial arteries combined with absence of other origins.

PubMed

Jie, Bing; Sun, Xi-Wen; Yu, Dong; Jiang, Sen

2014-08-01

There are numerous anatomical variations of the sites of origin of the bronchial arteries (BAs). A subclavian origin of a BA involves an aberrant artery that originates from the subclavian artery (SCA) or its branches. However, the aberrant artery usually originates directly from the SCA, and an SCA-origin BA arising from the branches of the SCA is rare. We herein present an extremely rare case of a right BA arising from the ipsilateral costocervical trunk, and a left BA arising from the ipsilateral thyrocervical trunk, in the absence of other origins of the BA. This anatomical variation was detected during pretherapeutic evaluation by multidetector-row computed tomography and confirmed by selective angiography. Recognition of these anatomic variations is important to surgical, diagnostic, and interventional radiologic procedures in the thorax.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van de Velde, Joris, E-mail: joris.vandevelde@ugent.be; Department of Radiotherapy, Ghent University, Ghent; Audenaert, Emmanuel

Purpose: To develop contouring guidelines for the brachial plexus (BP) using anatomically validated cadaver datasets. Magnetic resonance imaging (MRI) and computed tomography (CT) were used to obtain detailed visualizations of the BP region, with the goal of achieving maximal inclusion of the actual BP in a small contoured volume while also accommodating for anatomic variations. Methods and Materials: CT and MRI were obtained for 8 cadavers positioned for intensity modulated radiation therapy. 3-dimensional reconstructions of soft tissue (from MRI) and bone (from CT) were combined to create 8 separate enhanced CT project files. Dissection of the corresponding cadavers anatomically validatedmore » the reconstructions created. Seven enhanced CT project files were then automatically fitted, separately in different regions, to obtain a single dataset of superimposed BP regions that incorporated anatomic variations. From this dataset, improved BP contouring guidelines were developed. These guidelines were then applied to the 7 original CT project files and also to 1 additional file, left out from the superimposing procedure. The percentage of BP inclusion was compared with the published guidelines. Results: The anatomic validation procedure showed a high level of conformity for the BP regions examined between the 3-dimensional reconstructions generated and the dissected counterparts. Accurate and detailed BP contouring guidelines were developed, which provided corresponding guidance for each level in a clinical dataset. An average margin of 4.7 mm around the anatomically validated BP contour is sufficient to accommodate for anatomic variations. Using the new guidelines, 100% inclusion of the BP was achieved, compared with a mean inclusion of 37.75% when published guidelines were applied. Conclusion: Improved guidelines for BP delineation were developed using combined MRI and CT imaging with validation by anatomic dissection.« less

Variations in magnetic resonance venographic anatomy of the dorsal dural venous sinus system in 51 dogs.

PubMed

Fenn, Joe; Lam, Richard; Kenny, Patrick J

2013-01-01

Variations in intracranial dural venous sinus anatomy have been widely reported in humans, but there have been no studies reporting this in dogs. The purpose of this retrospective study was to describe variations in magnetic resonance (MR) venographic anatomy of the dorsal dural venous sinus system in a sample population of dogs with structurally normal brains. Medical records were searched for dogs with complete phase contrast, intracranial MR venograms and a diagnosis of idiopathic epilepsy. Magnetic resonance venograms were retrieved for each dog and characteristics of the dorsal dural sinuses, symmetry of the transverse sinuses and other anatomic variations were recorded. A total of 51 dogs were included. Transverse sinus asymmetry was present in 58.8% of the dogs, with transverse sinus hypoplasia seen in 39.2%, and aplasia in 23.5% of dogs. For 70.6% of dogs, at least one anatomic variation in the dorsal sagittal sinus was observed, including deviation from the midline (33.3%) and collateral branches from either the dorsal sagittal sinus or dorsal cerebral veins (54.9%). In 5 dogs (9.8%) a vessel was also identified running from the proximal transverse sinus to the distal sigmoid sinus, in a similar location to the occipital sinus previously reported in children. Findings from this study indicated that, as in humans, anatomic variations are common in the intracranial dural venous sinus system of dogs. These anatomic variations should be taken into consideration for surgical planning or diagnosis of cerebrovascular disease. © 2013 Veterinary Radiology & Ultrasound.

COMPUTED TOMOGRAPHIC APPEARANCE OF THE TEMPOROMANDIBULAR JOINT IN 1018 ASYMPTOMATIC HORSES: A MULTI-INSTITUTION STUDY.

PubMed

Carmalt, James L; Kneissl, Sibylle; Rawlinson, Jennifer E; Zwick, Timo; Zekas, Lisa; Ohlerth, Stefanie; Bienert-Zeit, Astrid

2016-05-01

Published descriptions of nonseptic arthritis of the equine temporomandibular joint (TMJ) are rare and large studies investigating variations in the TMJ for asymptomatic horses are lacking. The objectives of this cross-sectional, retrospective, multi-institutional study were to describe anatomical variations in the TMJ detected using computed tomography (CT) in an equid population asymptomatic for TMJ disease and determine whether these variations were associated with patient signalment, reason for CT examination, or CT slice width. Medical records at eight hospitals were searched for horses that had head/neck CT scans and no clinical signs of TMJ disease. Age, breed, sex, clinical presentation, and CT slice width data were recorded. Alterations in CT contour and density of the mandibular condyles, mandibular fossae, and TMJ intra-articular discs were described for each horse. Generalized logistic regression was used to test associations between anatomical variations and horse age. A total of 1018 horses were sampled. Anatomical variations were found in TMJ CT images for 40% of horses and 29% of joints. These were dichotomous with regard to age. Horses <1 year old commonly had alterations in the shape and density of the mandibular condyle. Older horses commonly had spherical hypodensities within the mandibular condyles consistent with bone cysts; and hyperdense regions of the intra-articular disc consistent with dystrophic mineralization. Findings indicated that TMJ anatomic variations were common in CT images of younger and older horses asymptomatic for TMJ disease. Future studies are needed to more definitively characterize these CT variations using gross pathology and histopathology. © 2016 American College of Veterinary Radiology.

Correction of partial volume effect in (18)F-FDG PET brain studies using coregistered MR volumes: voxel based analysis of tracer uptake in the white matter.

PubMed

Coello, Christopher; Willoch, Frode; Selnes, Per; Gjerstad, Leif; Fladby, Tormod; Skretting, Arne

2013-05-15

A voxel-based algorithm to correct for partial volume effect in PET brain volumes is presented. This method (named LoReAn) is based on MRI based segmentation of anatomical regions and accurate measurements of the effective point spread function of the PET imaging process. The objective is to correct for the spill-out of activity from high-uptake anatomical structures (e.g. grey matter) into low-uptake anatomical structures (e.g. white matter) in order to quantify physiological uptake in the white matter. The new algorithm is presented and validated against the state of the art region-based geometric transfer matrix (GTM) method with synthetic and clinical data. Using synthetic data, both bias and coefficient of variation were improved in the white matter region using LoReAn compared to GTM. An increased number of anatomical regions doesn't affect the bias (<5%) and misregistration affects equally LoReAn and GTM algorithms. The LoReAn algorithm appears to be a simple and promising voxel-based algorithm for studying metabolism in white matter regions. Copyright © 2013 Elsevier Inc. All rights reserved.

Anatomical variation of celiac axis, superior mesenteric artery, and hepatic artery: Evaluation with multidetector computed tomography angiography.

PubMed

Farghadani, Maryam; Momeni, Mohammad; Hekmatnia, Ali; Momeni, Fateme; Baradaran Mahdavi, Mohammad Mehdi

2016-01-01

The celiac axis, superior mesenteric artery (SMA), and hepatic artery are the most important branches of abdominal aorta due to their vascularization field. The aim of our study was to evaluate the prevalence of different anatomical variation of celiac axis, SMA, hepatic artery, and its branches with multidetector computed tomography (MDCT) angiography of upper abdomen arteries. MDCT of 607 kidney donor and traumatic patients that referred to MDCT unit at Al Zahra Hospital in Isfahan from 2012 to 2015 were retrospectively evaluated. We excluded patients with history of abdominal vascular surgery and hepatic or pancreatic surgery. Computed tomography images of the patient were obtained with 64-row MDCT scanner and anatomical variations were analyzed. Three hundred and eighty-eight (63.9%) of the 607 patients had classic arterial anatomy and 219 (36.1%) patients had variant types. The most common type of variation was the origin of the right hepatic artery (RHA) from SMA (9.6%), and the next common variation was the origin of the left hepatic artery (LHA) from the left gastric artery (6.9%). Variations in the origin of the common hepatic artery (CHA) were seen in 16 (2.6%) patients. Buhler arc was identified in two patients. The RHA originated from the celiac axis in 11 (1.8%) patients and from the aorta in 8 (1.3%) patients. Trifurcation of CHA into gastroduodenal artery, RHA, and LHA was detected in 11 (1.8%) patients. The results of the present study showed that anatomical variation occurs in a high percentage of patients. Detection of these variations can guide surgical and radiological interventional planning.

How Does Leaf Anatomy Influence Water Transport outside the Xylem?1[OPEN

PubMed Central

Buckley, Thomas N.; Scoffoni, Christine; Sack, Lawren

2015-01-01

Leaves are arguably the most complex and important physicobiological systems in the ecosphere. Yet, water transport outside the leaf xylem remains poorly understood, despite its impacts on stomatal function and photosynthesis. We applied anatomical measurements from 14 diverse species to a novel model of water flow in an areole (the smallest region bounded by minor veins) to predict the impact of anatomical variation across species on outside-xylem hydraulic conductance (Kox). Several predictions verified previous correlational studies: (1) vein length per unit area is the strongest anatomical determinant of Kox, due to effects on hydraulic pathlength and bundle sheath (BS) surface area; (2) palisade mesophyll remains well hydrated in hypostomatous species, which may benefit photosynthesis, (3) BS extensions enhance Kox; and (4) the upper and lower epidermis are hydraulically sequestered from one another despite their proximity. Our findings also provided novel insights: (5) the BS contributes a minority of outside-xylem resistance; (6) vapor transport contributes up to two-thirds of Kox; (7) Kox is strongly enhanced by the proximity of veins to lower epidermis; and (8) Kox is strongly influenced by spongy mesophyll anatomy, decreasing with protoplast size and increasing with airspace fraction and cell wall thickness. Correlations between anatomy and Kox across species sometimes diverged from predicted causal effects, demonstrating the need for integrative models to resolve causation. For example, (9) Kox was enhanced far more in heterobaric species than predicted by their having BS extensions. Our approach provides detailed insights into the role of anatomical variation in leaf function. PMID:26084922

Biophysical modelling of intra-ring variations in tracheid features and wood density of Pinus pinaster trees exposed to seasonal droughts.

PubMed

Wilkinson, Sarah; Ogée, Jérôme; Domec, Jean-Christophe; Rayment, Mark; Wingate, Lisa

2015-03-01

Process-based models that link seasonally varying environmental signals to morphological features within tree rings are essential tools to predict tree growth response and commercially important wood quality traits under future climate scenarios. This study evaluated model portrayal of radial growth and wood anatomy observations within a mature maritime pine (Pinus pinaster (L.) Aït.) stand exposed to seasonal droughts. Intra-annual variations in tracheid anatomy and wood density were identified through image analysis and X-ray densitometry on stem cores covering the growth period 1999-2010. A cambial growth model was integrated with modelled plant water status and sugar availability from the soil-plant-atmosphere transfer model MuSICA to generate estimates of cell number, cell volume, cell mass and wood density on a weekly time step. The model successfully predicted inter-annual variations in cell number, ring width and maximum wood density. The model was also able to predict the occurrence of special anatomical features such as intra-annual density fluctuations (IADFs) in growth rings. Since cell wall thickness remained surprisingly constant within and between growth rings, variations in wood density were primarily the result of variations in lumen diameter, both in the model and anatomical data. In the model, changes in plant water status were identified as the main driver of the IADFs through a direct effect on cell volume. The anatomy data also revealed that a trade-off existed between hydraulic safety and hydraulic efficiency. Although a simplified description of cambial physiology is presented, this integrated modelling approach shows potential value for identifying universal patterns of tree-ring growth and anatomical features over a broad climatic gradient. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Computed tomography angiography study of variations of the celiac trunk and hepatic artery in 100 patients.

PubMed

Brasil, Ivelise Regina Canito; de Araujo, Igor Farias; Lima, Adriana Augusta Lopes de Araujo; Melo, Ernesto Lima Araujo; Esmeraldo, Ronaldo de Matos

2018-01-01

To describe the main anatomical variations of the celiac trunk and the hepatic artery at their origins. This was a prospective analysis of 100 consecutive computed tomography angiography studies of the abdomen performed during a one-year period. The findings were stratified according to classification systems devised by Sureka et al. and Michels. The celiac trunk was "normal" (i.e., the hepatogastrosplenic trunk and superior mesenteric artery originating separately from the abdominal aorta) in 43 patients. In our sample, we identified four types of variations of the celiac trunk. Regarding the hepatic artery, a normal anatomical pattern (i.e., the proper hepatic artery being a continuation of the common hepatic artery and bifurcating into the right and left hepatic arteries) was seen in 82 patients. We observed six types of variations of the hepatic artery. We found rates of variations of the hepatic artery that are different from those reported in the literature. Our findings underscore the need for proper knowledge and awareness of these anatomical variations, which can facilitate their recognition and inform decisions regarding the planning of surgical procedures, in order to avoid iatrogenic intraoperative injuries, which could lead to complications.

Anatomical variations of hepatic arterial system, coeliac trunk and renal arteries: an analysis with multidetector CT angiography.

PubMed

Ugurel, M S; Battal, B; Bozlar, U; Nural, M S; Tasar, M; Ors, F; Saglam, M; Karademir, I

2010-08-01

The purpose of our investigation was to determine the anatomical variations in the coeliac trunk-hepatic arterial system and the renal arteries in patients who underwent multidetector CT (MDCT) angiography of the abdominal aorta for various reasons. A total of 100 patients were analysed retrospectively. The coeliac trunk, hepatic arterial system and renal arteries were analysed individually and anatomical variations were recorded. Statistical analysis of the relationship between hepatocoeliac variations and renal artery variations was performed using a chi(2) test. There was a coeliac trunk trifurcation in 89% and bifurcation in 8% of the cases. Coeliac trunk was absent in 1%, a hepatosplenomesenteric trunk was seen in 1% and a splenomesenteric trunk was present in 1%. Hepatic artery variation was present in 48% of patients. Coeliac trunk and/or hepatic arterial variation was present in 23 (39.7%) of the 58 patients with normal renal arteries, and in 27 (64.3%) of the 42 patients with accessory renal arteries. There was a statistically significant correlation between renal artery variations and coeliac trunk-hepatic arterial system variations (p = 0.015). MDCT angiography permits a correct and detailed evaluation of hepatic and renal vascular anatomy. The prevalence of variations in the coeliac trunk and/or hepatic arteries is increased in people with accessory renal arteries. For that reason, when undertaking angiographic examinations directed towards any single organ, the possibility of variations in the vascular structure of other organs should be kept in mind.

CT imaging-based determination and classification of anatomic variations of left gastric vein.

PubMed

Wu, Yongyou; Chen, Guangqiang; Wu, Pengfei; Zhu, Jianbin; Peng, Wei; Xing, Chungen

2017-03-01

Precise determination and classification of left gastric vein (LGV) anatomy are helpful in planning for gastric surgery, in particular, for resection of gastric cancer. However, the anatomy of LGV is highly variable. A systematic classification of its variations is still to be proposed. We aimed to investigate the anatomical variations in LGV using CT imaging and develop a new nomenclature system. We reviewed CT images and tracked the course of LGV in 825 adults. The frequencies of common and variable LGV anatomical courses were recorded. Anatomic variations of LGV were proposed and classified into different types mainly based on its courses. The inflow sites of LGV into the portal system were also considered if common hepatic artery (CHA) or splenic artery (SA) could not be used as a frame of reference due to variations. Detailed anatomy and courses of LGV were depicted on CT images. Using CHA and SA as the frames of reference, the routes of LGV were divided into six types (i.e., PreS, RetroS, Mid, PreCH, RetroCH, and Supra). The inflow sites were classified into four types (i.e., PV, SV, PSV, and LPV). The new classification was mainly based on the courses of LGV, which was validated with MDCT in the 805 cases with an identifiable LGV, namely type I, RetroCH, 49.8 % (401/805); type II, PreS, 20.6 % (166/805); type III, Mid, 20.0 % (161/805); type IV, RetroS, 7.3 % (59/805); type V, Supra, 1.5 % (12/805); and type VI, PreCH, 0.7 % (6/805). Type VII, designated to the cases in which SA and CHA could not be used as frames of reference, was not observed in this series. Detailed depiction of the anatomy and courses of LGV on CT images allowed us to evaluate and develop a new classification and nomenclature system for the anatomical variations of LGV.

Learning-based stochastic object models for characterizing anatomical variations

NASA Astrophysics Data System (ADS)

Dolly, Steven R.; Lou, Yang; Anastasio, Mark A.; Li, Hua

2018-03-01

It is widely known that the optimization of imaging systems based on objective, task-based measures of image quality via computer-simulation requires the use of a stochastic object model (SOM). However, the development of computationally tractable SOMs that can accurately model the statistical variations in human anatomy within a specified ensemble of patients remains a challenging task. Previously reported numerical anatomic models lack the ability to accurately model inter-patient and inter-organ variations in human anatomy among a broad patient population, mainly because they are established on image data corresponding to a few of patients and individual anatomic organs. This may introduce phantom-specific bias into computer-simulation studies, where the study result is heavily dependent on which phantom is used. In certain applications, however, databases of high-quality volumetric images and organ contours are available that can facilitate this SOM development. In this work, a novel and tractable methodology for learning a SOM and generating numerical phantoms from a set of volumetric training images is developed. The proposed methodology learns geometric attribute distributions (GAD) of human anatomic organs from a broad patient population, which characterize both centroid relationships between neighboring organs and anatomic shape similarity of individual organs among patients. By randomly sampling the learned centroid and shape GADs with the constraints of the respective principal attribute variations learned from the training data, an ensemble of stochastic objects can be created. The randomness in organ shape and position reflects the learned variability of human anatomy. To demonstrate the methodology, a SOM of an adult male pelvis is computed and examples of corresponding numerical phantoms are created.

How well do contoured superior midshaft clavicle plates fit the clavicle? A cadaveric study.

PubMed

Malhas, Amar M; Skarparis, Yiannis G; Sripada, Sankar; Soames, Roger W; Jariwala, Arpit C

2016-06-01

Given the degree of variation in clavicular morphology, 4 clavicle plating systems were examined for their congruity as superior, midshaft, anatomic clavicle (SMAC) plates in a cadaveric study. SMAC plates from 4 manufacturers were applied to 79 dry right human clavicles. Two systems offered multiple (4) variations of plates (MP), 1 offered two variations (TP), and 1 had a single plate (SP). Two examiners applied and clamped the best-fitting plate from each system onto each of the 79 clavicles and then graded them: 1, poor fit; 2, good fit; and 3, anatomic fit. Each examiner repeated the process to assess intraobserver and interobserver reliability. The scores were averaged to produce a final score for each system for each clavicle. The MP systems scored the highest (32%-37% anatomic, 54%-63% good, 5%-8% poor), followed by the TP system (30% anatomic, 53% good, 17% poor), and finally the SP system (9% anatomic, 59% good, 32% poor). Of note, clavicular length significantly correlated with a higher degree of conformity in all plating systems (Spearman rank correlation P < .05 for each system). In clavicles longer than 150 mm, the MP and TP systems performed identically, with the SP system close behind. Contouring of the plate is needed in 73% of cases overall. Plating systems with multiple plate shape variations are more advantageous when dealing with smaller-sized clavicles, typically in females. However, when dealing with larger clavicles, there was no real difference. Copyright © 2016 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

Impact of anatomical variations of the circle of Willis on the incidence of aneurysms and their recurrence rate following endovascular treatment.

PubMed

Songsaeng, D; Geibprasert, S; Willinsky, R; Tymianski, M; TerBrugge, K G; Krings, T

2010-11-01

To analyse the impact of anatomical variations of the parent arteries on the incidence and recurrence rate following coil embolization of aneurysms of the anterior (AcoA), posterior communicating artery (PcoA) and basilar artery (BA) tip. Two hundred and two (96 AcoA, 67 PcoA, and 29 BA) aneurysms in 200 patients were treated with coil embolization between January 2000 and April 2008. Parent artery variations at each location were classified as: AcoA: A1 aplasia versus hypoplasia versus symmetrical size; PcoA: foetal origin versus medium versus small size, BA: cranial versus caudal versus asymmetrical fusion. The incidence of aneurysms and difference between recurrence rates for each group were recorded on follow-up. AcoA, PcoA, and BA aneurysms were more often associated with embryonically earlier vessel wall dispositions (A1 aplasia, foetal PcoA, asymmetrical fusion). Two of these variations were also associated with aneurysm recurrence following coil embolization: asymmetrical A1 segment (p=0.01), and asymmetrical BA tip (p=0.02). AcoA, PcoA, and BA tip aneurysms tend to occur more often in anatomically variant parent artery dispositions, some of which are related to aneurysm recurrence following coil embolization. This may relate to a more fragile vessel disposition as it is not fully matured or to altered haemodynamics secondary to the anatomical variations. Copyright © 2010 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

Patterns and Variations in Microvascular Decompression for Trigeminal Neuralgia

PubMed Central

TODA, Hiroki; GOTO, Masanori; IWASAKI, Koichi

2015-01-01

Microvascular decompression (MVD) is a highly effective surgical treatment for trigeminal neuralgia (TN). Although there is little prospective clinical evidence, accumulated observational studies have demonstrated the benefits of MVD for refractory TN. In the current surgical practice of MVD for TN, there have been recognized patterns and variations in surgical anatomy and various decompression techniques. Here we provide a stepwise description of surgical procedures and relevant anatomical characteristics, as well as procedural options. PMID:25925756

The effect of the presence of the accessory maxillary ostium on the maxillary sinus.

PubMed

Yenigun, Alper; Fazliogullari, Zeliha; Gun, Cihat; Uysal, Ismihan Ilknur; Nayman, Alaaddin; Karabulut, Ahmet Kagan

2016-12-01

This study was conducted to investigate the presence of the accessory maxillary ostium and its effects on the maxillary sinus, and the concurrent occurrence of morphological variations of neighboring anatomical structures. This study was performed in a tertiary referral center. This is a cross-sectional retrospective study that evaluated coronal CTs of patients to determine the frequency of the accessory maxillary ostium and investigated any simultaneous morphological variations in neighboring anatomical structures. The presence of the accessory maxillary ostium (AMO) plus any concurrent morphological variations of neighboring structures were investigated in 377 patients, with 754 sides. AMO was found to be present in 19.1 % (72/377) of the patients. A concurrent mucus retention cyst was found to be statistically significant on both sides (right side: p = 0.00, left side: p = 0.00), as well as mucosal thickening (right side: p = 0.00, left side: p = 0.00), and maxillary sinusitis (right side: p = 0.04, left side: p = 0.03). No other concurrent variations of statistical significance were detected in the neighboring structures. Our study demonstrated that with the presence of AMO, the likelihood of encountering a mucus retention cyst (48.6 %) had an approximately threefold increase, and that of encountering mucosal thickening (43.0 %) and maxillary sinusitis (29.1 %) had a twofold increase.

MRI Findings of Intrinsic and Extrinsic Duodenal Abnormalities and Variations

PubMed Central

Erden, Ayse; Ustuner, Evren; Uzun, Caglar; Bektas, Mehmet

2015-01-01

This pictorial review aims to illustrate the magnetic resonance imaging (MRI) findings and presentation patterns of anatomical variations and various benign and malignant pathologies of the duodenum, including sphincter contraction, major papilla variation, prominent papilla, diverticulum, annular pancreas, duplication cysts, choledochocele, duodenal wall thickening secondary to acute pancreatitis, postbulbar stenosis, celiac disease, fistula, choledochoduodenostomy, external compression, polyps, Peutz-Jeghers syndrome, ampullary carcinoma and adenocarcinoma. MRI is a useful imaging tool for demonstrating duodenal pathology and its anatomic relationships with adjacent organs, which is critical for establishing correct diagnosis and planning appropriate treatment, especially for surgery. PMID:26576112

Anatomical and morphological study of the subcoracoacromial canal.

PubMed

Le Reun, O; Lebhar, J; Mateos, F; Voisin, J L; Thomazeau, H; Ropars, M

2016-12-01

Many clinical anatomy studies have looked into how variations in the acromion, coracoacromial ligament (CAL) and subacromial space are associated with rotator cuff injuries. However, no study up to now had defined anatomically the fibro-osseous canal that confines the supraspinatus muscle in the subcoracoacromial space. Through an anatomical study of the scapula, we defined the bone-related parameters of this canal and its anatomical variations. This study on dry bones involved 71 scapulas. With standardised photographs in two orthogonal views (superior and lateral), the surface area of the subcoracoacromial canal and the anatomical parameters making up this canal were defined and measured using image analysis software. The primary analysis evaluated the anatomical parameters of the canal as a function of three canal surface area groups; the secondary analysis looked into how variations in the canal surface area were related to the type of acromion according to the Bigliani classification. Relative to glenoid width, the group with a large canal surface area (L) had significantly less lateral overhang of the acromion than the group with a small canal surface area (S), with ratios of 0.41±0.23 and 0.58±0.3, respectively (P=0.04). The mean length of the CAL was 46±8mm in the L group and 39±9mm in the S group (P=0.003). The coracoacromial arch angle was 38°±11° in the L group and 34°±9° in the S group; the canal surface area was smaller in specimens with a smaller coracoacromial arch angle (P=0.20). Apart from acromial morphology, there could be innate anatomical features of the scapula that predispose people to extrinsic lesions to the supraspinatus tendon (lateral overhang, coracoacromial arch angle) by reducing the subcoracoacromial canal's surface area. Anatomical descriptive study. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Anatomical Variations of the Right Adrenal Vein: Concordance Between Multidetector Computed Tomography and Catheter Venography.

PubMed

Omura, Kensuke; Ota, Hideki; Takahashi, Yuuki; Matsuura, Tomonori; Seiji, Kazumasa; Arai, Yoichi; Morimoto, Ryo; Satoh, Fumitoshi; Takase, Kei

2017-03-01

Adrenal venous sampling is the most reliable diagnostic procedure to determine surgical indications in primary aldosteronism. Because guidelines recommend multidetector computed tomography (CT) to evaluate the adrenal gland, some past reports used multidetector CT as a guide for adrenal venous sampling. However, the detailed anatomy of the right adrenal vein and its relationship with an accessory hepatic vein remains uncertain. The purpose of this study was to describe detailed anatomical variations of the right adrenal vein and to determine the concordance between CT and catheter venography in patients with primary aldosteronism. In total, 440 consecutive patients who underwent adrenal venous sampling were included. Four-phase dynamic CT was performed. Anatomical locations and variations of the right adrenal vein and its relationship with the accessory hepatic vein were compared with catheter venographic findings. Successful catheterization was achieved in 437 patients (99%). The right adrenal vein was visualized in the late arterial phase with CT in 420 patients (95%). The right adrenal vein formed a common trunk with the accessory hepatic vein in 87 patients (20%). CT identified the correct craniocaudal level of the orifice in 354 patients (84%). Anatomical variations, location, and angle of inflow of the right adrenal vein based on CT demonstrated high concordance with catheter venography. CT may provide useful information for preparation before adrenal venous sampling. © 2017 American Heart Association, Inc.

A rare variation of the digastric muscle

PubMed Central

KALNIEV, MANOL; KRASTEV, DIMO; KRASTEV, NIKOLAY; VIDINOV, KALIN; VELTCHEV, LUDMIL; APOSTOLOV, ALEXANDER; MILEVA, MILKA

2013-01-01

The digastric muscle is composed by two muscle bellies: an anterior and a posterior, joined by an intermediate tendon. This muscle is situated in the anterior region of the neck. The region between the hyoid bone and the mandible is divided by an anterior belly into two triangles: the submandibular situated laterally and the submental triangle which is located medially. We found that the anatomical variations described in the literature relate mainly to the anterior belly and consist of differences in shape and attachment of the muscle. During routine dissection in February 2013 in the section hall of the Department of Anatomy and Histology in Medical University – Sofia we came across a very interesting variation of the digastric muscle. The digastric muscles that presented anatomical variations were photographed using a Sony Cyber-shot DSC-T1 camera, with a Carl Zeiss Vario-Tessar lens. We found out bilateral variation of the digastric muscle in one cadaver. The anterior bellies were very thin and insert to the hyoid bone. Two anterior bellies connect each other and thus they formed a loop. The anatomical variations observed of our study related only to the anterior belly, as previously described by other authors. It is very important to consider the occurrence of the above mentioned variations in the digastric muscle when surgical procedures are performed on the anterior region of the neck. PMID:26527971

Fabrication and Assessment of 3D Printed Anatomical Models of the Lower Limb for Anatomical Teaching and Femoral Vessel Access Training in Medicine

ERIC Educational Resources Information Center

O'Reilly, Michael K.; Reese, Sven; Herlihy, Therese; Geoghegan, Tony; Cantwell, Colin P.; Feeney, Robin N. M.; Jones, James F. X.

2016-01-01

For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail. However, a new teaching construct has appeared recently in which artificial…

Influence of the middle ear anatomy on the performance of a membrane sensor in the incudostapedial joint gap.

PubMed

Koch, Martin; Seidler, Hannes; Hellmuth, Alexander; Bornitz, Matthias; Lasurashvili, Nikoloz; Zahnert, Thomas

2013-07-01

There is a great demand for implantable microphones for future generations of implantable hearing aids, especially Cochlea Implants. An implantable middle ear microphone based on a piezoelectric membrane sensor for insertion into the incudostapedial gap is investigated. The sensor is designed to measure the sound-induced forces acting on the center of the membrane. The sensor mechanically couples to the adjacent ossicles via two contact areas, the sensor membrane and the sensor housing. The sensing element is a piezoelectric single crystal bonded on a titanium membrane. The sensor allows a minimally invasive and reversible implantation without removal of ossicles and without additional sensor fixation in the tympanic cavity. This study investigates the implantable microphone sensor and its implantation concept. It intends to quantify the influence of the sensor's insertion position on the achievable microphone sensitivity. The investigation considers anatomical and pathological variations of the middle ear geometry and its space limitations. Temporal bone experiments on a laboratory model show that anatomical and pathological variations of the middle ear geometry can prevent the sensor from being placed optimally within the incudostapedial joint. Beyond scattering of transfer functions due to anatomic variations of individual middle ears there is the impact of variations in the sensor position within the ossicular chain that has a considerable effect on the transfer characteristics of the middle ear microphone. The centering of the sensor between incus and stapes, the direction of insertion (membrane to stapes or to incus) and the effect of additional contact points with surrounding anatomic structures affect the signal yield of the implanted sensor. The presence of additional contact points has a considerably impact on the sensitivity, yet the microphone sensitivity is quite robust against small changes in the positioning of the incus on the sensor. Signal losses can be avoided by adjusting the position of the sensor within the joint. The findings allow the development of an improved surgical insertion technique to ensure maximally achievable signal yield of the membrane sensor in the ISJ and provides valuable knowledge for a future design considerations including sensor miniaturization and geometry. Measurements of the implanted sensor in temporal bone specimens showed a microphone sensitivity in the order of 1 mV/Pa. This article is part of a special issue entitled "MEMRO 2012". Copyright © 2012 Elsevier B.V. All rights reserved.

Paranasal sinus bony structures and sinus functioning during viral colds in subjects with and without a history of recurrent sinusitis.

PubMed

Alho, Olli-Pekka

2003-12-01

The objective was to assess the impact of ostial obstruction and anatomical variations on paranasal sinus functioning during viral colds with computed tomography (CT) in subjects with and without a history of sinusitis. Cross-sectional study. Twenty-three volunteers with a history of recurrent sinusitis and 25 subjects without such history who had an early (symptoms for 2-4 d) natural cold were examined by taking viral specimens and CT scans and recording symptoms. The pathological sinus changes in the CT scans were scored, and several paranasal bony anatomical variations recorded. Viral origin of the cold was identified in 32 (67%) subjects, similarly in the two groups. Ostiomeatal obstruction and anatomical variations were equally frequent in the subjects with and without a sinusitis history (17 of 23 vs. 17 of 25 for ostial obstruction and 17 of 23 vs. 20 of 25 for at least one variation, respectively). However, in the case of ostiomeatal obstruction the combined CT score of ethmoidal and maxillary sinuses was significantly higher in the subjects with a sinusitis history than in those without (mean +/- SD, 3.0 +/- 0.9 vs. 2.3 +/- 1.2 [P =.05, t test]). In the sinusitis-prone subjects, several variations were associated significantly with various pathological sinus CT changes (septal deviation, horizontally situated processus uncinatus, large concha bullosa, and laterally concave concha media), whereas in the control subjects, only the presence of Haller cells was related to sphenoidal sinus disease. Ostiomeatal complex obstruction and bony anatomical variations seem to have a greater impact on the functioning of paranasal sinuses during viral colds in sinusitis-prone subjects than in subjects without a sinusitis history. These differences may be associated with the increased risk of bacterial sinusitis.

Buntaro Adachi (1865-1945): Japanese master of human anatomic variation.

PubMed

Watanabe, Koichi; Shoja, Mohammadali M; Loukas, Marios; Tubbs, R Shane

2012-11-01

Buntaro Adachi (1865-1945) was a Japanese physician, anatomist, and anthropologist and is most remembered for his study on human anatomic variation. At the end of 19th Century, one of the main focuses in anthropology was the comparison between the races. In Japan, anthropological studies of the origin of the modern Japanese race were carried out by Adachi and others. Adachi believed that differences went beyond the bones that were commonly studied in his day and, therefore, investigated soft tissues of the body. Two products of his intense study of variation of human anatomy were Das Arteriensystem der Japaner (The Arterial System of the Japanese) published in 1928 and Das Venensystem der Japaner (The Venous System of the Japanese) published in 1933 and 1940. These books received much attention and were praised by anatomists and anthropologists around the world. Even now, these books are invaluable as references for human anatomic variation. Herein, we provide an overview of the life and achievements of Buntaro Adachi and to our knowledge, this is the first such review in the English language. Copyright © 2012 Wiley Periodicals, Inc.

Broad Anatomical Variation within a Narrow Wood Density Range--A Study of Twig Wood across 69 Australian Angiosperms.

PubMed

Ziemińska, Kasia; Westoby, Mark; Wright, Ian J

2015-01-01

Just as people with the same weight can have different body builds, woods with the same wood density can have different anatomies. Here, our aim was to assess the magnitude of anatomical variation within a restricted range of wood density and explore its potential ecological implications. Twig wood of 69 angiosperm tree and shrub species was analyzed. Species were selected so that wood density varied within a relatively narrow range (0.38-0.62 g cm-3). Anatomical traits quantified included wood tissue fractions (fibres, axial parenchyma, ray parenchyma, vessels, and conduits with maximum lumen diameter below 15 μm), vessel properties, and pith area. To search for potential ecological correlates of anatomical variation the species were sampled across rainfall and temperature contrasts, and several other ecologically-relevant traits were measured (plant height, leaf area to sapwood area ratio, and modulus of elasticity). Despite the limited range in wood density, substantial anatomical variation was observed. Total parenchyma fraction varied from 0.12 to 0.66 and fibre fraction from 0.20 to 0.74, and these two traits were strongly inversely correlated (r = -0.86, P < 0.001). Parenchyma was weakly (0.24 ≤|r|≤ 0.35, P < 0.05) or not associated with vessel properties nor with height, leaf area to sapwood area ratio, and modulus of elasticity (0.24 ≤|r|≤ 0.41, P < 0.05). However, vessel traits were fairly well correlated with height and leaf area to sapwood area ratio (0.47 ≤|r|≤ 0.65, all P < 0.001). Modulus of elasticity was mainly driven by fibre wall plus vessel wall fraction rather than by the parenchyma component. Overall, there seem to be at least three axes of variation in xylem, substantially independent of each other: a wood density spectrum, a fibre-parenchyma spectrum, and a vessel area spectrum. The fibre-parenchyma spectrum does not yet have any clear or convincing ecological interpretation.

Dorsal metacarpal veins: anatomic variation and potential clinical implications.

PubMed

Elmegarhi, Sara S; Amarin, Justin Z; Hadidi, Maher T; Badran, Darwish H; Massad, Islam M; Bani-Hani, Amjad M; Shatarat, Amjad T

2018-03-01

The dorsal metacarpal veins are frequently cannulated. Cannulation success is determined by several variable anatomic features. The objective of this study is to classify, for the first time, the anatomic variants of the dorsal metacarpal veins. In this cross-sectional study, 520 university students and staff were conveniently recruited. The dorsal metacarpal veins in 1040 hands were studied. Venous visibility was enhanced by either tourniquet application or near-infrared illumination. Variant patterns of the dorsal metacarpal veins were classified. The final analysis included 726 hands, for an exclusion rate of 30 %. Eight pattern types were identified. Three anatomic features informed the variation. Bilateral symmetry of the dorsal metacarpal veins was present in 352 participants (83 % of the total). The overall frequency distribution of variants in both hands was similar (P = 0.8). The frequency distribution of variants was subject to sexual dimorphism (P = 0.001), ethnic variation (P < 0.001), and technical variation (P < 0.001). The anatomic variants of the dorsal metacarpal veins were sorted into decreasingly frequent primary, secondary, and tertiary groups. The groups may signify a progressive increase in difficulty of peripheral cannulation, in the mentioned order. As such, primary patterns are the most common and likely the easiest to cannulate, while tertiary patterns are the least common and likely the most difficult to cannulate. The preceding premise, in tandem with the bilateral asymmetry of the veins, is clinically significant. With cannulation difficulty likely signifying an underlying tertiary pattern, the contralateral dorsal metacarpal veins are probabilistically characterized by a primary pattern and are, as such, the easier option for peripheral venous cannulation.

The Main Anatomic Variations of the Hepatic Artery and Their Importance in Surgical Practice: Review of the Literature.

PubMed

Noussios, George; Dimitriou, Ioannis; Chatzis, Iosif; Katsourakis, Anastasios

2017-04-01

Anatomical variations of the hepatic artery are important in the planning and performance of abdominal surgical procedures. Normal hepatic anatomy occurs in approximately 80% of cases, for the remaining 20% multiple variations have been described. The purpose of this study was to review the existing literature on the hepatic anatomy and to stress out its importance in surgical practice. Two main databases were searched for eligible articles during the period 2000 - 2015, and results concerning more than 19,000 patients were included in the study. The most common variation was the replaced right hepatic artery (type III according to Michels classification) which is the chief source of blood supply to the bile duct.

Anatomical variations of the thymus in relation to the left brachiocephalic vein, findings of necropsia.

PubMed

Plaza, Oscar Alonso; Moreno, Freddy

2018-04-01

Two cases of anatomical variations of the thymus are presented with respect to the anatomical relations with the left brachiocephalic vein and found during the necropsy process. Less than 2 days after birth with Noonan Syndrome, when the left brachiocephalic vein was scanning behind the upper thymus horns, there were other adjacent lesions consisting of three supernumerary spleens and three hepatic veins. The second case was an 8-year-old infant with child malpractice who died from urinary sepsis due to obstructive uropathy, in which case the upper lobes of the thymus were fused and formed a ring through which the left brachiocephalic vein passed. Copyright © 2018 Elsevier B.V. All rights reserved.

Leaf density explains variation in leaf mass per area in rice between cultivars and nitrogen treatments.

PubMed

Xiong, Dongliang; Wang, Dan; Liu, Xi; Peng, Shaobing; Huang, Jianliang; Li, Yong

2016-05-01

Leaf mass per area (LMA) is an important leaf trait; however, correlations between LMA and leaf anatomical features and photosynthesis have not been fully investigated, especially in cereal crops. The objectives of this study were (a) to investigate the correlations between LMA and leaf anatomical traits; and (b) to clarify the response of LMA to nitrogen supply and its effect on photosynthetic nitrogen use efficiency (PNUE). In the present study, 11 rice varieties were pot grown under sufficient nitrogen (SN) conditions, and four selected rice cultivars were grown under low nitrogen (LN) conditions. Leaf anatomical traits, gas exchange and leaf N content were measured. There was large variation in LMA across selected rice varieties. Regression analysis showed that the variation in LMA was more closely related to leaf density (LD) than to leaf thickness (LT). LMA was positively related to the percentage of mesophyll tissue area (%mesophyll), negatively related to the percentage of epidermis tissue area (%epidermis) and unrelated to the percentage of vascular tissue area (%vascular). The response of LMA to N supplementation was dependent on the variety and was also mainly determined by the response of LD to N. Compared with SN, photosynthesis was significantly decreased under LN, while PNUE was increased. The increase in PNUE was more critical in rice cultivars with a higher LMA under SN supply. Leaf density is the major cause of the variation in LMA across rice varieties and N treatments, and an increase in LMA under high N conditions would aggravate the decrease in PNUE. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Uberon, an integrative multi-species anatomy ontology

PubMed Central

2012-01-01

We present Uberon, an integrated cross-species ontology consisting of over 6,500 classes representing a variety of anatomical entities, organized according to traditional anatomical classification criteria. The ontology represents structures in a species-neutral way and includes extensive associations to existing species-centric anatomical ontologies, allowing integration of model organism and human data. Uberon provides a necessary bridge between anatomical structures in different taxa for cross-species inference. It uses novel methods for representing taxonomic variation, and has proved to be essential for translational phenotype analyses. Uberon is available at http://uberon.org PMID:22293552

Transsphenoidal surgery in patients with acromegaly: operative strategies for overcoming technically challenging anatomical variations.

PubMed

Zada, Gabriel; Cavallo, Luigi M; Esposito, Felice; Fernandez-Jimenez, Julio Cesar; Tasiou, Anastasia; De Angelis, Michelangelo; Cafiero, Tullio; Cappabianca, Paolo; Laws, Edward R

2010-10-01

In addition to difficulties with anesthetic and medical management, transsphenoidal operations in patients with longstanding acromegaly are associated with inherent intraoperative challenges because of anatomical variations that occur frequently in these patients. The object of this study was to review the overall safety profile and anatomical/technical challenges associated with transsphenoidal surgery in patients with acromegaly. The authors performed a retrospective analysis of 169 patients who underwent endoscopic transsphenoidal operations for growth hormone-secreting adenomas to assess the incidence of surgical complications. A review of frequently occurring anatomical challenges and operative strategies employed during each phase of the operation to address these particular issues was performed. Of 169 cases reviewed, there was no perioperative mortality. Internal carotid artery injury occurred in 1 patient (0.6%) with complex sinus anatomy, who remained neurologically intact following endovascular unilateral carotid artery occlusion. Other complications included: significant postoperative epistaxis (5 patients [3%]), transient diabetes insipidus (5 patients [3%]), delayed symptomatic hyponatremia (4 patients [2%]), CSF leak (2 patients [1%]), and pancreatitis (1 patient [0.6%]). Preoperative considerations in patients with acromegaly should include a cardiopulmonary evaluation and planning regarding intubation and other aspects of the anesthetic technique. During the nasal phase of the transsphenoidal operation, primary challenges include maintaining adequate visualization and hemostasis, which is frequently compromised by redundant, edematous nasal mucosa and bony hypertrophy of the septum and the nasal turbinates. During the sphenoid phase, adequate bony removal, optimization of working space, and correlation of imaging studies to intraoperative anatomy are major priorities. The sellar phase is frequently challenged by increased sellar floor thickness, distinct patterns of tumor extension and bony invasion, and anatomical variations in the caliber and course of the internal carotid artery. Specific operative techniques for addressing each of these intraoperative challenges are discussed. Transsphenoidal surgery in patients with longstanding acromegaly frequently poses greater challenges than operations for other types of sellar lesions, yet these challenges may be safely and effectively overcome with the anticipation of specific issues and implementation of various intraoperative techniques.

Anatomical robust optimization to account for nasal cavity filling variation during intensity-modulated proton therapy: a comparison with conventional and adaptive planning strategies

NASA Astrophysics Data System (ADS)

van de Water, Steven; Albertini, Francesca; Weber, Damien C.; Heijmen, Ben J. M.; Hoogeman, Mischa S.; Lomax, Antony J.

2018-01-01

The aim of this study is to develop an anatomical robust optimization method for intensity-modulated proton therapy (IMPT) that accounts for interfraction variations in nasal cavity filling, and to compare it with conventional single-field uniform dose (SFUD) optimization and online plan adaptation. We included CT data of five patients with tumors in the sinonasal region. Using the planning CT, we generated for each patient 25 ‘synthetic’ CTs with varying nasal cavity filling. The robust optimization method available in our treatment planning system ‘Erasmus-iCycle’ was extended to also account for anatomical uncertainties by including (synthetic) CTs with varying patient anatomy as error scenarios in the inverse optimization. For each patient, we generated treatment plans using anatomical robust optimization and, for benchmarking, using SFUD optimization and online plan adaptation. Clinical target volume (CTV) and organ-at-risk (OAR) doses were assessed by recalculating the treatment plans on the synthetic CTs, evaluating dose distributions individually and accumulated over an entire fractionated 50 GyRBE treatment, assuming each synthetic CT to correspond to a 2 GyRBE fraction. Treatment plans were also evaluated using actual repeat CTs. Anatomical robust optimization resulted in adequate CTV doses (V95%  ⩾  98% and V107%  ⩽  2%) if at least three synthetic CTs were included in addition to the planning CT. These CTV requirements were also fulfilled for online plan adaptation, but not for the SFUD approach, even when applying a margin of 5 mm. Compared with anatomical robust optimization, OAR dose parameters for the accumulated dose distributions were on average 5.9 GyRBE (20%) higher when using SFUD optimization and on average 3.6 GyRBE (18%) lower for online plan adaptation. In conclusion, anatomical robust optimization effectively accounted for changes in nasal cavity filling during IMPT, providing substantially improved CTV and OAR doses compared with conventional SFUD optimization. OAR doses can be further reduced by using online plan adaptation.

In vivo study of the surgical anatomy of the axilla.

PubMed

Khan, A; Chakravorty, A; Gui, G P H

2012-06-01

Classical anatomical descriptions fail to describe variants often observed in the axilla as they are based on studies that looked at individual structures in isolation or textbooks of cadaveric dissections. The presence of variant anatomy heightens the risk of iatrogenic injury. The aim of this study was to document the nature and frequency of these anatomical variations based on in vivo peroperative surgical observations. Detailed anatomical relationships were documented prospectively during consecutive axillary dissections. Relationships between the thoracodorsal pedicle, course of the lateral thoracic vein, presence of latissimus dorsi muscle slips, variations in axillary and angular vein anatomy, and origins and branching of the intercostobrachial nerve were recorded. Among a total of 73 axillary dissections, 43 (59 per cent) revealed at least one anatomical variant. Most notable variants included aberrant courses of the thoracodorsal nerve in ten patients (14 per cent)--three variants; lateral thoracic vein in 12 patients (16 per cent)--four variants; bifid axillary veins in ten patients (14 per cent); latissimus dorsi muscle slips in four patients (5 per cent); and variants in intercostobrachial nerve origins and branching in 26 patients (36 per cent). The angular vein, a subscapular vein tributary, was found to be a constant axillary structure. Variations in axillary anatomical structures are common. Poor understanding of these variants can affect the adequacy of oncological clearance, lead to vascular injury, compromise planned microvascular procedures and result in chronic pain or numbness from nerve injury. Surgeons should be aware of the common anatomical variants to facilitate efficient and safe axillary surgery. Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.

Using 3D modeling techniques to enhance teaching of difficult anatomical concepts

PubMed Central

Pujol, Sonia; Baldwin, Michael; Nassiri, Joshua; Kikinis, Ron; Shaffer, Kitt

2016-01-01

Rationale and Objectives Anatomy is an essential component of medical education as it is critical for the accurate diagnosis in organs and human systems. The mental representation of the shape and organization of different anatomical structures is a crucial step in the learning process. The purpose of this pilot study is to demonstrate the feasibility and benefits of developing innovative teaching modules for anatomy education of first-year medical students based on 3D reconstructions from actual patient data. Materials and Methods A total of 196 models of anatomical structures from 16 anonymized CT datasets were generated using the 3D Slicer open-source software platform. The models focused on three anatomical areas: the mediastinum, the upper abdomen and the pelvis. Online optional quizzes were offered to first-year medical students to assess their comprehension in the areas of interest. Specific tasks were designed for students to complete using the 3D models. Results Scores of the quizzes confirmed a lack of understanding of 3D spatial relationships of anatomical structures despite standard instruction including dissection. Written task material and qualitative review by students suggested that interaction with 3D models led to a better understanding of the shape and spatial relationships among structures, and helped illustrate anatomical variations from one body to another. Conclusion The study demonstrates the feasibility of one possible approach to the generation of 3D models of the anatomy from actual patient data. The educational materials developed have the potential to supplement the teaching of complex anatomical regions and help demonstrate the anatomic variation among patients. PMID:26897601

A Biomechanical Modeling Study of the Effects of the Orbicularis Oris Muscle and Jaw Posture on Lip Shape

ERIC Educational Resources Information Center

Stavness, Ian; Nazari, Mohammad Ali; Perrier, Pascal; Demolin, Didier; Payan, Yohan

2013-01-01

Purpose: The authors' general aim is to use biomechanical models of speech articulators to explore how possible variations in anatomical structure contribute to differences in articulatory strategies and phone systems across human populations. Specifically, they investigated 2 issues: (a) the link between lip muscle anatomy and variability in…

MR imaging assessment of the lateral head of the gastrocnemius muscle: prevalence of segmental anomalous origins in children and young adults.

PubMed

Kim, Hee Kyung; Laor, Tal; Racadio, Judy M

2008-12-01

Variations in the lower extremity musculature have been identified, including an anomalous origin of the medial head of the gastrocnemius muscle. Anomalies of the lateral head of the gastrocnemius muscle (LGN) have been less frequently described, especially in children. To describe the MR imaging appearance, frequency and clinical symptoms associated with anatomic variations of the LGN in children and young adults. A retrospective review of 465 knee MR imaging examinations was performed. The site of origin of the LGN was identified as either normal, lateral segmental anomalous origin (LSAO), or medial accessory anomalous origin (MAAO). The clinical indication for imaging was recorded. An anatomic variation of the LGN was identified in 16 patients (3.4%). Nine patients had LSAO, and five of these had symptoms referable to or abnormalities of the patella. Seven patients had MAAO, and three of these had chronic nontraumatic knee pain. Anatomic variations of the LGN are not rare in young patients, occurring with a frequency of 3.4% in our series. It is unknown whether these anomalies play a role in the etiology of patellofemoral pain or unexplained joint pain in children.

Atlas warping for brain morphometry

NASA Astrophysics Data System (ADS)

Machado, Alexei M. C.; Gee, James C.

1998-06-01

In this work, we describe an automated approach to morphometry based on spatial normalizations of the data, and demonstrate its application to the analysis of gender differences in the human corpus callosum. The purpose is to describe a population by a reduced and representative set of variables, from which a prior model can be constructed. Our approach is rooted in the assumption that individual anatomies can be considered as quantitative variations on a common underlying qualitative plane. We can therefore imagine that a given individual's anatomy is a warped version of some referential anatomy, also known as an atlas. The spatial warps which transform a labeled atlas into anatomic alignment with a population yield immediate knowledge about organ size and shape in the group. Furthermore, variation within the set of spatial warps is directly related to the anatomic variation among the subjects. Specifically, the shape statistics--mean and variance of the mappings--for the population can be calculated in a special basis, and an eigendecomposition of the variance performed to identify the most significant modes of shape variation. The results obtained with the corpus callosum study confirm the existence of substantial anatomical differences between males and females, as reported in previous experimental work.

Inter- and Intraspecific Variations in the Pectoral Muscles of Common Chimpanzees (Pan troglodytes), Bonobos (Pan paniscus), and Humans (Homo sapiens).

PubMed

Potau, J M; Arias-Martorell, J; Bello-Hellegouarch, G; Casado, A; Pastor, J F; de Paz, F; Diogo, R

2018-01-01

We have analyzed anatomic variations in the pectoralis major and pectoralis minor muscles of common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) and compared them to anatomic variations in these muscles in humans (Homo sapiens) . We have macroscopically dissected these muscles in six adult Pan troglodytes , five Pan paniscus of ages ranging from fetus to adult, and five adult Homo sapiens . Although Pan troglodytes are thought to lack a separate pectoralis abdominis muscle, we have identified this muscle in three of the Pan troglodytes ; none of the Pan paniscus , however, had this muscle. We have also found deep supernumerary fascicles in the pectoralis major of two Pan troglodytes and all five Pan paniscus . In all six Pan troglodytes , the pectoralis minor was inserted at the supraspinatus tendon, while, in Pan paniscus and Homo sapiens , it was inserted at the coracoid process of the scapula. Some of the anatomic features and variations of these muscles in common chimpanzees and bonobos are similar to those found in humans, therefore enhancing our knowledge of primate comparative anatomy and evolution and also shedding light on several clinical issues.

Inter- and Intraspecific Variations in the Pectoral Muscles of Common Chimpanzees (Pan troglodytes), Bonobos (Pan paniscus), and Humans (Homo sapiens)

PubMed Central

Arias-Martorell, J.; Bello-Hellegouarch, G.; Casado, A.; Pastor, J. F.; de Paz, F.; Diogo, R.

2018-01-01

We have analyzed anatomic variations in the pectoralis major and pectoralis minor muscles of common chimpanzees (Pan troglodytes) and bonobos (Pan paniscus) and compared them to anatomic variations in these muscles in humans (Homo sapiens). We have macroscopically dissected these muscles in six adult Pan troglodytes, five Pan paniscus of ages ranging from fetus to adult, and five adult Homo sapiens. Although Pan troglodytes are thought to lack a separate pectoralis abdominis muscle, we have identified this muscle in three of the Pan troglodytes; none of the Pan paniscus, however, had this muscle. We have also found deep supernumerary fascicles in the pectoralis major of two Pan troglodytes and all five Pan paniscus. In all six Pan troglodytes, the pectoralis minor was inserted at the supraspinatus tendon, while, in Pan paniscus and Homo sapiens, it was inserted at the coracoid process of the scapula. Some of the anatomic features and variations of these muscles in common chimpanzees and bonobos are similar to those found in humans, therefore enhancing our knowledge of primate comparative anatomy and evolution and also shedding light on several clinical issues. PMID:29581990

Anatomical Variations of the Biliary Tree Found with Endoscopic Retrograde Cholagiopancreatography in a Referral Center in Southern Iran.

PubMed

Taghavi, Seyed Alireza; Niknam, Ramin; Alavi, Seyed Ehsan; Ejtehadi, Fardad; Sivandzadeh, Gholam Reza; Eshraghian, Ahad

2017-10-01

BACKGROUND Anatomical variations in the biliary system have been proven to be of clinical importance. Awareness of the pattern of these variations in a specific population may help to prevent and manage biliary injuries during surgical and endoscopic procedures. Knowledge of the biliary anatomy will be also of great help in planning the drainage of adequate percentage of liver parenchyma in endoscopic or radiological procedures. METHODS All consecutive patients undergoing endoscopic retrograde cholangiopancreatography (ERCP) from April 2013 to April 2015 at Nemazee Hospital, a referral center in the south of Iran, were included in this cross-sectional study. The patients with previous hepatic or biliary surgery, liver injury or destructive biliary disease were excluded from the study. All ERCPs were reviewed by two expert gastroenterologists in this field. The disagreed images by the two gastroenterologists were excluded. Huang classification was used for categorizing the different structural variants of the biliary tree, and the frequency of each variant was recorded. RESULTS Totally, 362 patients (181 men and 181 women) were included in the study. 163 patients (45%) had type A1 Huang classification (right dominant), which was the most prevalent type among our patients. 55% of them had non-right dominant anatomy. The result of the Chi-square test revealed that there was no statistically significant difference between the men and women regarding the anatomical variations (p = 0.413). CONCLUSION The anatomical variation in the biliary system among Iranian patients is comparable to other regions of the world. Significant proportions of our patients are non-right dominant and may need bilateral biliary drainage.

Incidence of Branching Patterns Variations of the Arch in Aortic Dissection in Chinese Patients

PubMed Central

Tapia, G. Pullas; Zhu, Xiaohua; Xu, Jing; Liang, Pan; Su, Gang; Liu, Hai; Liu, Yang; Shu, Liliang; Liu, Shuiqi; Huang, Chen

2015-01-01

Abstract Several authors have described anatomic variations of the aortic arch in 13% to 20% of the patients who do not have aortic disease. However, few studies have evaluated these patterns in the thoracic aortic dissection (TAD). In the authors’ knowledge, this is the first survey that specifically investigates the frequency of these variations in a broad, nonselected group of Chinese patients with aortic dissection. Furthermore, it compares this group with a group of patients without aortic disease. The objective of this study was to define the variation frequency of the aortic arch branches pattern using the tomographic studies of 525 Chinese patients with a diagnosis of TAD. The Stanford classification was used to set the site of the initial tear of the dissection. In addition, we performed an epidemiological analysis of the aortic arch anatomic variations in TAD, and its possible implications for surgical or endovascular treatment. The general hypothesis proposal asserted that Chinese patients with dissection of the aorta have a similar incidence of variations of the aortic arch to the patients without aortic disease. A retrospective study of cases and controls was carried out using the tomographic studies (CT) of all patients admitted to the First Affiliated Hospital of Zhengzhou University, located at Henan-China, with a confirmed diagnosis of aortic dissection from January 2012 until December 2014. The group of cases consisted of 525 patients: 374 men and 151 women, with a mean age of 52.27 years (range, 20–89). The average age of the patients with Stanford A and B aortic dissection was 49.46 and 53.67, respectively. The control group consisted of 525 unselected patients without TAD who underwent a CT scan of the chest due to other indications. This group consisted of 286 men and 239 women, with a mean age of 53.60 years (range, 18–89). All the patients with aneurysm or dissection were excluded from the control group. We performed a statistical analysis of demographic data. The study found 7 different patterns of the aortic arch on both groups of cases and controls. Within the 525 patients with TAD were observed 85 (16.19%) anatomical variations, while the control group showed 112 variations (21.33%); P = 0.033. The most common anatomical variant was the bovine arch, found in 62 (11.80%) cases of TAD compared with 77 (14.66%) in the control group; P = 0.172. Anatomical variations were observed in 14.32% of the patients with Stanford A dissection and 17.09% of the patients with Stanford B dissection; P = 0.425. Patients with Stanford A dissection showed the pattern of bovine arch in 23 (13.21%) of 174 cases. In contrast, the patients with Stanford B dissection showed it in 39 (11.11%) of 351 cases; P = 0.481. The anatomical variant defined as vertebral artery of direct origin of the aortic arch was more frequent in the patients with Stanford B dissection (5.12%). The patients with Stanford A dissection presented this pattern in 1.14% of the cases; P = 0.025. This study observed an increased frequency of aortic dissection in the subgroup from 41 to 60 years old. In the subgroup from 41 to 60 years old without TAD, a greater frequency of anatomical variations were found than in the patients with TAD (20.81% vs 14.23%; P = 0.050). The same fashion was seen in patients older than 80 years (27.27% vs 0%; P = 0.030). The anatomical variations of the aortic arch with TAD occurred in 14.97% of the male patients and 19.20% of the female patients compared to 21.67% to 20.92% in the control group; P = 0.026 and P = 0.681, respectively. The aortic arch variations were found less frequently in the TAD group than in the control group in the present Chinese series. The bovine arch was considered the variant pattern of the major frequency in the patients with TAD and the control group. The anatomical variant of 4 branches, defined as vertebral artery of direct origin of the aortic arch, was more frequent in patients with Stanford B aortic dissection than in the patients with Stanford A. This finding might show an association between the geometry of the aortic arch and the site of onset of first intimal tear of dissection. PMID:25929931

Incidence of branching patterns variations of the arch in aortic dissection in Chinese patients.

PubMed

Tapia, G Pullas; Zhu, Xiaohua; Xu, Jing; Liang, Pan; Su, Gang; Liu, Hai; Liu, Yang; Shu, Liliang; Liu, Shuiqi; Huang, Chen

2015-05-01

Several authors have described anatomic variations of the aortic arch in 13% to 20% of the patients who do not have aortic disease. However, few studies have evaluated these patterns in the thoracic aortic dissection (TAD). In the authors' knowledge, this is the first survey that specifically investigates the frequency of these variations in a broad, nonselected group of Chinese patients with aortic dissection. Furthermore, it compares this group with a group of patients without aortic disease.The objective of this study was to define the variation frequency of the aortic arch branches pattern using the tomographic studies of 525 Chinese patients with a diagnosis of TAD. The Stanford classification was used to set the site of the initial tear of the dissection. In addition, we performed an epidemiological analysis of the aortic arch anatomic variations in TAD, and its possible implications for surgical or endovascular treatment. The general hypothesis proposal asserted that Chinese patients with dissection of the aorta have a similar incidence of variations of the aortic arch to the patients without aortic disease.A retrospective study of cases and controls was carried out using the tomographic studies (CT) of all patients admitted to the First Affiliated Hospital of Zhengzhou University, located at Henan-China, with a confirmed diagnosis of aortic dissection from January 2012 until December 2014. The group of cases consisted of 525 patients: 374 men and 151 women, with a mean age of 52.27 years (range, 20-89). The average age of the patients with Stanford A and B aortic dissection was 49.46 and 53.67, respectively. The control group consisted of 525 unselected patients without TAD who underwent a CT scan of the chest due to other indications. This group consisted of 286 men and 239 women, with a mean age of 53.60 years (range, 18-89). All the patients with aneurysm or dissection were excluded from the control group. We performed a statistical analysis of demographic data.The study found 7 different patterns of the aortic arch on both groups of cases and controls. Within the 525 patients with TAD were observed 85 (16.19%) anatomical variations, while the control group showed 112 variations (21.33%); P = 0.033. The most common anatomical variant was the bovine arch, found in 62 (11.80%) cases of TAD compared with 77 (14.66%) in the control group; P = 0.172. Anatomical variations were observed in 14.32% of the patients with Stanford A dissection and 17.09% of the patients with Stanford B dissection; P = 0.425. Patients with Stanford A dissection showed the pattern of bovine arch in 23 (13.21%) of 174 cases. In contrast, the patients with Stanford B dissection showed it in 39 (11.11%) of 351 cases; P = 0.481. The anatomical variant defined as vertebral artery of direct origin of the aortic arch was more frequent in the patients with Stanford B dissection (5.12%). The patients with Stanford A dissection presented this pattern in 1.14% of the cases; P = 0.025. This study observed an increased frequency of aortic dissection in the subgroup from 41 to 60 years old. In the subgroup from 41 to 60 years old without TAD, a greater frequency of anatomical variations were found than in the patients with TAD (20.81% vs 14.23%; P = 0.050). The same fashion was seen in patients older than 80 years (27.27% vs 0%; P = 0.030). The anatomical variations of the aortic arch with TAD occurred in 14.97% of the male patients and 19.20% of the female patients compared to 21.67% to 20.92% in the control group; P = 0.026 and P = 0.681, respectively.The aortic arch variations were found less frequently in the TAD group than in the control group in the present Chinese series. The bovine arch was considered the variant pattern of the major frequency in the patients with TAD and the control group. The anatomical variant of 4 branches, defined as vertebral artery of direct origin of the aortic arch, was more frequent in patients with Stanford B aortic dissection than in the patients with Stanford A.This finding might show an association between the geometry of the aortic arch and the site of onset of first intimal tear of dissection.

Effects of spatial variation of skull and cerebrospinal fluid layers on optical mapping of brain activities

NASA Astrophysics Data System (ADS)

Wang, Shuping; Shibahara, Nanae; Kuramashi, Daishi; Okawa, Shinpei; Kakuta, Naoto; Okada, Eiji; Maki, Atsushi; Yamada, Yukio

2010-07-01

In order to investigate the effects of anatomical variation in human heads on the optical mapping of brain activity, we perform simulations of optical mapping by solving the photon diffusion equation for layered-models simulating human heads using the finite element method (FEM). Particularly, the effects of the spatial variations in the thicknesses of the skull and cerebrospinal fluid (CSF) layers on mapping images are investigated. Mapping images of single active regions in the gray matter layer are affected by the spatial variations in the skull and CSF layer thicknesses, although the effects are smaller than those of the positions of the active region relative to the data points. The increase in the skull thickness decreases the sensitivity of the images to active regions, while the increase in the CSF layer thickness increases the sensitivity in general. The images of multiple active regions are also influenced by their positions relative to the data points and by their depths from the skin surface.

A meta-analysis of inferior thyroid artery variations in different human ethnic groups and their clinical implications.

PubMed

Toni, Roberto; Casa, Claudia Della; Castorina, Sergio; Roti, Elio; Ceda, Gianpaolo; Valenti, Giorgio

2005-09-01

We have recently found ethnic differences in superior thyroid artery (STA) variational anatomy. Therefore, we now focus on the inferior thyroid artery (ITA). In particular, we analyze whether presence, numerical variations and site of origin of ITA are influenced by ethnic group and gender, whether and which neck side has the largest arterial caliber, whether differences occur between the presence of ITA and STA, to which extent a non-selective thyroid angiography is effective in visualizing ITA, also in comparison to STA, and which clinical value this information may have in selected pathologies of the thyroid, parathyroid and larynx. A meta-analysis has been performed, including 33 library- and Medline-selected publications on Caucasoids (European and non-European) and East Asians, and a set of original data on European Caucasoids. A total of 6285 Caucasoid and 847 East Asian items, comprising half bodies and arteries, were analyzed. After testing the homogeneity of the available data sources in relation to the anatomical variables under study we calculated a cumulative value for each selected anatomical parameter and evaluated differences using non-parametric statistics. The effectiveness of non-selective thyroid angiography was determined using sensitivity, specificity, positive and negative predictive values. The ITA was more frequently absent in East Asians than in Caucasoids, and respectively either more or less frequently arising from thyrocervical and subclavian arteries, in East Asians versus Caucasoids. In contrast, the ITA was less frequently present both in Caucasoids and East Asians than the STA. In addition, the ITA was more frequently present on the right than on the left side in both ethnic groups, but no neck side predominated in size of arterial caliber in European Caucasoids. Finally, the ITA was more frequently present in East Asian males than females, and the effectiveness of a non-selective thyroid angiography showed higher numbers for ITA than STA in Caucasoids. Statistically significant variations occur in some ITA parameters between Caucasoids and East Asians, and in its presence with respect to STA, within each ethnic group. These differences, together with a sexual dimorphic presence of ITA in East Asians and high effectiveness of its visualization by non-selective angiography in European Caucasoids, may represent an evidence-based supply of anatomical information for analysis in selected pathologies of the thyroid, parathyroid and larynx.

Effect of anatomy on human nasal air flow and odorant transport patterns: implications for olfaction.

PubMed

Zhao, Kai; Scherer, Peter W; Hajiloo, Shoreh A; Dalton, Pamela

2004-06-01

Recent studies that have compared CT or MRI images of an individual's nasal anatomy and measures of their olfactory sensitivity have found a correlation between specific anatomical areas and performance on olfactory assessments. Using computational fluid dynamics (CFD) techniques, we have developed a method to quickly (

The 4D hyperspherical diffusion wavelet: A new method for the detection of localized anatomical variation.

PubMed

Hosseinbor, Ameer Pasha; Kim, Won Hwa; Adluru, Nagesh; Acharya, Amit; Vorperian, Houri K; Chung, Moo K

2014-01-01

Recently, the HyperSPHARM algorithm was proposed to parameterize multiple disjoint objects in a holistic manner using the 4D hyperspherical harmonics. The HyperSPHARM coefficients are global; they cannot be used to directly infer localized variations in signal. In this paper, we present a unified wavelet framework that links Hyper-SPHARM to the diffusion wavelet transform. Specifically, we will show that the HyperSPHARM basis forms a subset of a wavelet-based multiscale representation of surface-based signals. This wavelet, termed the hyperspherical diffusion wavelet, is a consequence of the equivalence of isotropic heat diffusion smoothing and the diffusion wavelet transform on the hypersphere. Our framework allows for the statistical inference of highly localized anatomical changes, which we demonstrate in the first-ever developmental study on the hyoid bone investigating gender and age effects. We also show that the hyperspherical wavelet successfully picks up group-wise differences that are barely detectable using SPHARM.

The 4D Hyperspherical Diffusion Wavelet: A New Method for the Detection of Localized Anatomical Variation

PubMed Central

Hosseinbor, A. Pasha; Kim, Won Hwa; Adluru, Nagesh; Acharya, Amit; Vorperian, Houri K.; Chung, Moo K.

2014-01-01

Recently, the HyperSPHARM algorithm was proposed to parameterize multiple disjoint objects in a holistic manner using the 4D hyperspherical harmonics. The HyperSPHARM coefficients are global; they cannot be used to directly infer localized variations in signal. In this paper, we present a unified wavelet framework that links HyperSPHARM to the diffusion wavelet transform. Specifically, we will show that the HyperSPHARM basis forms a subset of a wavelet-based multiscale representation of surface-based signals. This wavelet, termed the hyperspherical diffusion wavelet, is a consequence of the equivalence of isotropic heat diffusion smoothing and the diffusion wavelet transform on the hypersphere. Our framework allows for the statistical inference of highly localized anatomical changes, which we demonstrate in the firstever developmental study on the hyoid bone investigating gender and age effects. We also show that the hyperspherical wavelet successfully picks up group-wise differences that are barely detectable using SPHARM. PMID:25320783

Morphological, anatomical, and ultrastructural changes (visualized through scanning electron microscopy) induced in Triticum aestivum by Pb²⁺ treatment.

PubMed

Kaur, Gurpreet; Singh, Harminder Pal; Batish, Daizy Rani; Kohli, Ravinder Kumar

2014-11-01

Lead (Pb) causes severe damage to crops, ecosystems, and humans, and alters the physiology and biochemistry of various plant species. It is hypothesized that Pb-induced metabolic alterations could manifest as structural variations in the roots of plants. In light of this, the morphological, anatomical, and ultrastructural variations (through scanning electron microscopy, SEM) were studied in 4-day-old seedlings of Triticum aestivum grown under Pb stress (0, 8, 16, 40, and 80 mg Pb(2+) l(-1); mild to highly toxic). The toxic effect was more pronounced in radicle growth than on the plumule growth. The SEM of the root of T. aestivum depicted morphological alterations and surface ultrastructural changes. Compared to intact and uniform surface cells in the control roots, cells were irregular and desiccated in Pb(2+)-treated roots. In Pb(2+)-treated roots, the number of root hairs increased manifold, showing dense growth, and these were apparently longer. Apart from the deformity in surface morphology and anatomy of the roots in response to Pb(2+) toxicity, considerable anatomical alterations were also observed. Pb(2+)-treated root exhibited signs of injury in the form of cell distortion, particularly in the cortical cells. The endodermis and pericycle region showed loss of uniformity post Pb(2+) exposure (at 80 mg l(-1) Pb(2+)). The cells appeared to be squeezed with greater depositions observed all over the tissue. The study concludes that Pb(2+) treatment caused structural anomalies and induced anatomical and surface ultrastructural changes in T. aestivum.

Palmaris Longus Muscle's Prevalence in Different Nations and Interesting Anatomical Variations: Review of the Literature.

PubMed

Ioannis, Dimitriou; Anastasios, Katsourakis; Konstantinos, Natsis; Lazaros, Kostretzis; Georgios, Noussios

2015-11-01

The prevalence of the palmaris longus (PL) muscle varies more than any other muscle in the human body. Its absence across the world ranges between 1.5% and 63.9%. It presents with many different anomalies, discovered either clinically, intraoperatively or after anatomical examination of cadavers. This paper includes recent studies and reports about the presence and variations of the PL muscle, thereby illustrating the differences between ethnic groups, as well as emphasizing the different ways of finding it, during daily clinical and surgical practice.

Broad Anatomical Variation within a Narrow Wood Density Range—A Study of Twig Wood across 69 Australian Angiosperms

PubMed Central

Ziemińska, Kasia; Westoby, Mark; Wright, Ian J.

2015-01-01

Objectives Just as people with the same weight can have different body builds, woods with the same wood density can have different anatomies. Here, our aim was to assess the magnitude of anatomical variation within a restricted range of wood density and explore its potential ecological implications. Methods Twig wood of 69 angiosperm tree and shrub species was analyzed. Species were selected so that wood density varied within a relatively narrow range (0.38–0.62 g cm-3). Anatomical traits quantified included wood tissue fractions (fibres, axial parenchyma, ray parenchyma, vessels, and conduits with maximum lumen diameter below 15 μm), vessel properties, and pith area. To search for potential ecological correlates of anatomical variation the species were sampled across rainfall and temperature contrasts, and several other ecologically-relevant traits were measured (plant height, leaf area to sapwood area ratio, and modulus of elasticity). Results Despite the limited range in wood density, substantial anatomical variation was observed. Total parenchyma fraction varied from 0.12 to 0.66 and fibre fraction from 0.20 to 0.74, and these two traits were strongly inversely correlated (r = -0.86, P < 0.001). Parenchyma was weakly (0.24 ≤|r|≤ 0.35, P < 0.05) or not associated with vessel properties nor with height, leaf area to sapwood area ratio, and modulus of elasticity (0.24 ≤|r|≤ 0.41, P < 0.05). However, vessel traits were fairly well correlated with height and leaf area to sapwood area ratio (0.47 ≤|r|≤ 0.65, all P < 0.001). Modulus of elasticity was mainly driven by fibre wall plus vessel wall fraction rather than by the parenchyma component. Conclusions Overall, there seem to be at least three axes of variation in xylem, substantially independent of each other: a wood density spectrum, a fibre-parenchyma spectrum, and a vessel area spectrum. The fibre-parenchyma spectrum does not yet have any clear or convincing ecological interpretation. PMID:25906320

Anatomic Variation in Intrahepatic Bile Ducts: an Analysis of Intraoperative Cholangiograms in 300 Consecutive Donors for Living Donor Liver Transplantation

PubMed Central

Choi, Jin Woo; Kim, Kyoung Won; Kim, Ah Young; Kim, Pyo Nyun; Ha, Hyun Kwon; Lee, Moon-Gyu

2003-01-01

Objective To describe the anatomical variation occurring in intrahepatic bile ducts (IHDs) in terms of their branching patterns, and to determine the frequency of each variation. Materials and Methods The study group consisted of 300 consecutive donors for liver transplantation who underwent intraoperative cholangiography. Anatomical variation in IHDs was classified according to the branching pattern of the right anterior and right posterior segmental duct (RASD and RPSD, respectively), and the presence or absence of the first-order branch of the left hepatic duct (LHD), and of an accessory hepatic duct. Results The anatomy of the intrahepatic bile ducts was typical in 63% of cases (n=188), showed triple confluence in 10% (n=29), anomalous drainage of the RPSD into the LHD in 11% (n=34), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 6% (n=19), anomalous drainage of the RPSD into the cystic duct in 2% (n=6), drainage of the right hepatic duct (RHD) into the cystic duct (n=1), the presence of an accessory duct leading to the CHD or RHD in 5% (n=16), individual drainage of the LHD into the RHD or CHD in 1% (n=4), and unclassified or complex variation in 1% (n=3). Conclusion The branching pattern of IHDs was atypical in 37% of cases. The two most common variations were drainage of the RPSD into the LHD (11%) and triple confluence of the RASD, RPSD and LHD (10%). PMID:12845303

Anatomic variations in intrahepatic bile ducts in a north Indian population.

PubMed

Sharma, Vijay; Saraswat, Vivek Anand; Baijal, Sanjay Saran; Choudhuri, Gourdas

2008-07-01

In the present study, we described the anatomical variations in the branching patterns of intrahepatic bile ducts (IHD) and determined the frequency of each variation in north Indian patients. There are no data from India. The study group consisted of 253 consecutive patients (131 women) undergoing endoscopic retrograde cholangiograms for different indications. Anatomical variations in IHD were classified according to the branching pattern of the right anterior segmental duct (RASD) and the right posterior segmental duct (RPSD), presence or absence of first-order branch of left hepatic duct (LHD) and of an accessory hepatic duct. Anatomy of the IHD was typical in 52.9% of cases (n = 134), showing triple confluence in 11.46% (n = 29), anomalous drainage of the RPSD into the LHD in 18.2% (n = 46), anomalous drainage of the RPSD into the common hepatic duct (CHD) in 7.1% (n = 18), drainage of the right hepatic duct (RHD) into the cystic duct 0.4% (n = 1), presence of an accessory duct leading to the CHD or RHD in 4.7% (n = 12), individual drainage of the LHD into the RHD or CHD in 2.4% (n = 6), and unclassified or complex variations in 2.7% (n = 7). None had anomalous drainage of RPSD into the cystic duct. The branching pattern of IHD was atypical in 47% patients. The two most common variations were drainage of the RPSD into the LHD (18.2%) and triple confluence of the RASD, RPSD, and LHD (11.5%).

Pelvi-ureteric junction obstruction related to crossing vessels: vascular anatomic variations and implication for surgical approaches.

PubMed

Panthier, Frédéric; Lareyre, Fabien; Audouin, Marie; Raffort, Juliette

2018-03-01

Pelvi-ureteric junction obstruction corresponds to an impairment of urinary transport that can lead to renal dysfunction if not treated. Several mechanisms can cause the obstruction of the ureter including intrinsic factors or extrinsic factors such as the presence of crossing vessels. The treatment of the disease relies on surgical approaches, pyeloplasty being the standard reference. The technique consists in removing the pathologic ureteric segment and renal pelvis and transposing associated crossing vessels if present. The vascular anatomy of the pelvi-ureteric junction is complex and varies among individuals, and this can impact on the disease development and its surgical treatment. In this review, we summarize current knowledge on vascular anatomic variations in the pelvi-ureteric junction. Based on anatomic characteristics, we discuss implications for surgical approaches during pyeloplasty and vessel transposition.

Posterior inferior cerebellar artery aneurysms: Anatomical variations and surgical strategies

PubMed Central

Singh, Rohit K.; Behari, Sanjay; Kumar, Vijendra; Jaiswal, Awadhesh K.; Jain, Vijendra K.

2012-01-01

Context: Posterior inferior cerebellar artery (PICA) aneurysms are associated with multiple anatomical variations of the parent vessel. Complexities in their surgical clipping relate to narrow corridors limited by brain-stem, petrous-occipital bones, and multiple neurovascular structures occupying the cerebellomedullary and cerebellopontine cisterns. Aims: The present study focuses on surgical considerations during clipping of saccular PICA aneurysms. Setting and Design: Tertiary care, retrospective study. Materials and Methods: In 20 patients with PICA aneurysms, CT angiogram/digital substraction angiogram was used to correlate the site and anatomical variations of aneurysms located on different segments of PICA with the approach selected, the difficulties encountered and the final outcome. Statistical Analysis: Comparison of means and percentages. Results: Aneurysms were located on PICA at: vertebral artery/basilar artery (VA/BA)-PICA (n=5); anterior medullary (n=4); lateral medullary (n=3); tonsillomedullary (n=4); and, telovelotonsillar (n=4) segments. The Hunt and Hess grade distribution was I in 15; II in 2; and, III in 3 patients (mean ictus-surgery interval: 23.5 days; range: 3-150 days). Eight patients had hydrocephalus. Anatomical variations included giant, thrombosed aneurysms; 2 PICA aneurysms proximal to an arteriovenous malformation; bilobed or multiple aneurysms; low PICA situated at the foramen magnum with a hypoplastic VA; and fenestrated PICA. The approaches included a retromastoid suboccipital craniectomy (n=9); midline suboccipital craniectomy (n=6); and far-lateral approach (n=5). At a follow-up (range 6 months-2.5 years), 13 patients had no deficits (modified Rankin score (mRS) 0); 2 were symptomatic with no significant disability (mRS1); 1 had mild disability (mRS2); 1 had moderately severe disability (mRS4); and 3 died (mRS6). Three mortalities were caused by vasospasm (2) and, rupture of unclipped second VA-BA junctional aneurysm (1). Conclusions: PICA aneurysms may present with only IVth ventricular blood without subarachnoid hemorrhage. PICA may have multiple anomalies and its aneurysms may be missed on CT angiograms. Surgical approach is influenced by VA-BA tortuosity and variations in anatomy, location of the VA-BA junction and the PICA aneurysm relative to the brain-stem, and the pattern of collateral supply. The special category of VA-PICA junctional aneurysms and its management; and, the multiple anatomical variations of PICA aneurysms, merit special surgical considerations and have been highlighted in this study. PMID:22639684

Preliminary Study on Appearance-Based Detection of Anatomical Point Landmarks in Body Trunk CT Images

NASA Astrophysics Data System (ADS)

Nemoto, Mitsutaka; Nomura, Yukihiro; Hanaoka, Shohei; Masutani, Yoshitaka; Yoshikawa, Takeharu; Hayashi, Naoto; Yoshioka, Naoki; Ohtomo, Kuni

Anatomical point landmarks as most primitive anatomical knowledge are useful for medical image understanding. In this study, we propose a detection method for anatomical point landmark based on appearance models, which include gray-level statistical variations at point landmarks and their surrounding area. The models are built based on results of Principal Component Analysis (PCA) of sample data sets. In addition, we employed generative learning method by transforming ROI of sample data. In this study, we evaluated our method with 24 data sets of body trunk CT images and obtained 95.8 ± 7.3 % of the average sensitivity in 28 landmarks.

Anatomical basis of variation in mesophyll resistance in eastern Australian sclerophylls: news of a long and winding path

PubMed Central

Tosens, Tiina

2012-01-01

In sclerophylls, photosynthesis is particularly strongly limited by mesophyll diffusion resistance from substomatal cavities to chloroplasts (r m), but the controls on diffusion limits by integral leaf variables such as leaf thickness, density, and dry mass per unit area and by the individual steps along the diffusion pathway are imperfectly understood. To gain insight into the determinants of r m in leaves with varying structure, the full CO2 physical diffusion pathway was analysed in 32 Australian species sampled from sites contrasting in soil nutrients and rainfall, and having leaf structures from mesophytic to strongly sclerophyllous. r m was estimated based on combined measurements of gas exchange and chlorophyll fluorescence. In addition, r m was modelled on the basis of detailed anatomical measurements to separate the importance of different serial resistances affecting CO2 diffusion into chloroplasts. The strongest sources of variation in r m were S c/S, the exposed surface area of chloroplasts per unit leaf area, and mesophyll cell wall thickness, t cw. The strong correlation of r m with t cw could not be explained by cell wall thickness alone, and most likely arose from a further effect of cell wall porosity. The CO2 drawdown from intercellular spaces to chloroplasts was positively correlated with t cw, suggesting enhanced diffusional limitations in leaves with thicker cell walls. Leaf thickness and density were poorly correlated with S c/S, indicating that widely varying combinations of leaf anatomical traits occur at given values of leaf integrated traits, and suggesting that detailed anatomical studies are needed to predict r m for any given species. PMID:22888123

Anatomical study of variations in the blood supply of kidneys.

PubMed

Aristotle, Sharmila; Sundarapandian; Felicia, Christilda

2013-08-01

Each kidney is supplied by a single renal artery and a single renal vein, which accounts for about 20% of the cardiac output. However, variations in the form of level of origin and arrangement of renal arteries are so frequent. The present study aimed to note the vascular anatomy of kidneys with respect to the variations in their origin, course and any aberrant vessels which were present. The study material comprised of 15 formalin fixed human cadavers. During routine abdominal dissection for undergraduate students, the kidneys were exposed and the blood supply, along with its variations, were noted. The following anatomical findings are observed in this study: (i) Accessory renal arteries (ii) Presegmental arteries (iii) Upper polar arteries (iv) Lower polar arteries (v) Inferior suprarenal artery from accessory renal artery and (vi) Accessory renal vein. Awareness of the normal as well variational anatomy is mandatory for the surgeons, radiologists and urologists, for doing any uroradiological procedures or angiographic studies. Hence, this study will serve a useful guideline for the above mentioned procedures.

A Need for Logical and Consistent Anatomical Nomenclature for Cutaneous Nerves of the Limbs

ERIC Educational Resources Information Center

Gest, Thomas R.; Burkel, William E.; Cortright, Gerald W.

2009-01-01

The system of anatomical nomenclature needs to be logical and consistent. However, variations in translation to English of the Latin and Greek terminology used in Nomina Anatomica and Terminologia Anatomica have led to some inconsistency in the nomenclature of cutaneous nerves in the limbs. An historical review of cutaneous nerve nomenclature…

The female knee: anatomic variations.

PubMed

Conley, Sheryl; Rosenberg, Aaron; Crowninshield, Roy

2007-01-01

Traditional knee implants have been designed "down the middle,"based on the combined average size and shape of male and female knee anatomy.Sex-based research in the field of orthopaedics has led to new understanding of the anatomic differences between the sexes and the associated implications for women undergoing total knee arthroplasty. Through the use of a comprehensive bone morphology atlas that utilizes novel three-dimensional computed tomography analysis technology, significant anatomic differences have been documented in the shape and size of female knees compared with male knees. This research identifies three notable anatomic differences in the female population: a less prominent anterior condyle, an increased Q angle, and a reduced medial-lateral:anterior-posterior aspect ratio.

Evaluation of influences of the Viennese Anatomical School on the work of the Croatian Anatomist Jelena Krmpotic-Nemanic.

PubMed

Dinjar, Kristijan; Toth, Jurica; Atalic, Bruno; Radanovic, Danijela; Maric, Svjetlana

2012-01-01

This paper tries to evaluate the connections between the Viennese Anatomical School and the Croatian Anatomist Jelena Krmpotic-Nemanic. 17 papers written by Professor Jelena Krmpotic-Nemanic in the last decade of her life were chosen for analyses. According to their themes they could be divided into three groups: ones which evaluate the anatomical terminology, ones which research the development of anatomical structures, and ones which describe the anatomical variations. Mentioned papers were analysed through their topics, methods of research and cited references. Analyses of the mentioned papers revealed the indirect link between the Viennese Anatomical School and the Professor Jelena Krmpotic-Nemanic, through her mentor Professor Drago Perovic, regarding the themes and the methods of her anatomical researches. It has also showed her preference for Austrian and German anatomical textbooks and atlases, primarily ones published in Vienna and Jena, rather than English and American ones. Finally, her direct connections with the Viennese Institute for the History of Medicine and the Viennese Josephinum Wax Models Museum were emphasized. Mentioned indirect and direct influences of the Viennese Anatomical School on the work of Professor Jelena Krmpotic-Nemanic were critically appraised.

Variations and asymmetries in regional brain surface in the genus Homo.

PubMed

Balzeau, Antoine; Holloway, Ralph L; Grimaud-Hervé, Dominique

2012-06-01

Paleoneurology is an important field of research within human evolution studies. Variations in size and shape of an endocast help to differentiate among fossil hominin species whereas endocranial asymmetries are related to behavior and cognitive function. Here we analyse variations of the surface of the frontal, parieto-temporal and occipital lobes among different species of Homo, including 39 fossil hominins, ten fossil anatomically modern Homo sapiens and 100 endocasts of extant modern humans. We also test for the possible asymmetries of these features in a large sample of modern humans and observe individual particularities in the fossil specimens. This study contributes important new information about the brain evolution in the genus Homo. Our results show that the general pattern of surface asymmetry for the different regional brain surfaces in fossil species of Homo does not seem to be different from the pattern described in a large sample of anatomically modern H. sapiens, i.e., the right hemisphere has a larger surface than the left, as do the right frontal, the right parieto-temporal and the left occipital lobes compared with the contra-lateral side. It also appears that Asian Homo erectus specimens are discriminated from all other samples of Homo, including African and Georgian specimens that are also sometimes included in that taxon. The Asian fossils show a significantly smaller relative size of the parietal and temporal lobes. Neandertals and anatomically modern H. sapiens, who share the largest endocranial volume of all hominins, show differences when considering the relative contribution of the frontal, parieto-temporal and occipital lobes. These results illustrate an original variation in the pattern of brain organization in hominins independent of variations in total size. The globularization of the brain and the enlargement of the parietal lobes could be considered derived features observed uniquely in anatomically modern H. sapiens. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of anatomical variation on trainee performance in a virtual reality temporal bone surgery simulator.

PubMed

Piromchai, P; Ioannou, I; Wijewickrema, S; Kasemsiri, P; Lodge, J; Kennedy, G; O'Leary, S

2017-01-01

To investigate the importance of anatomical variation in acquiring skills in virtual reality cochlear implant surgery. Eleven otolaryngology residents participated in this study. They were randomly allocated to practice cochlear implant surgery on the same specimen or on different specimens for four weeks. They were then tested on two new specimens, one standard and one challenging. Videos of their performance were de-identified and reviewed independently, by two blinded consultant otolaryngologists, using a validated assessment scale. The scores were compared between groups. On the standard specimen, the round window preparation score was 2.7 ± 0.4 for the experimental group and 1.7 ± 0.6 for the control group (p = 0.01). On the challenging specimen, instrument handling and facial nerve preservation scores of the experimental group were 3.0 ± 0.4 and 3.5 ± 0.7 respectively, while the control group received scores of 2.1 ± 0.8 and 2.4 ± 0.9 respectively (p < 0.05). Training on temporal bones with differing anatomies is beneficial in the development of expertise.

The trait contribution to wood decomposition rates of 15 Neotropical tree species.

PubMed

van Geffen, Koert G; Poorter, Lourens; Sass-Klaassen, Ute; van Logtestijn, Richard S P; Cornelissen, Johannes H C

2010-12-01

The decomposition of dead wood is a critical uncertainty in models of the global carbon cycle. Despite this, relatively few studies have focused on dead wood decomposition, with a strong bias to higher latitudes. Especially the effect of interspecific variation in species traits on differences in wood decomposition rates remains unknown. In order to fill these gaps, we applied a novel method to study long-term wood decomposition of 15 tree species in a Bolivian semi-evergreen tropical moist forest. We hypothesized that interspecific differences in species traits are important drivers of variation in wood decomposition rates. Wood decomposition rates (fractional mass loss) varied between 0.01 and 0.31 yr(-1). We measured 10 different chemical, anatomical, and morphological traits for all species. The species' average traits were useful predictors of wood decomposition rates, particularly the average diameter (dbh) of the tree species (R2 = 0.41). Lignin concentration further increased the proportion of explained inter-specific variation in wood decomposition (both negative relations, cumulative R2 = 0.55), although it did not significantly explain variation in wood decomposition rates if considered alone. When dbh values of the actual dead trees sampled for decomposition rate determination were used as a predictor variable, the final model (including dead tree dbh and lignin concentration) explained even more variation in wood decomposition rates (R2 = 0.71), underlining the importance of dbh in wood decomposition. Other traits, including wood density, wood anatomical traits, macronutrient concentrations, and the amount of phenolic extractives could not significantly explain the variation in wood decomposition rates. The surprising results of this multi-species study, in which for the first time a large set of traits is explicitly linked to wood decomposition rates, merits further testing in other forest ecosystems.

Multiple cerebral arteriovenous malformations associated to rostral hypoplasia of the superior sagittal sinus: case report.

PubMed

TORNè, Ramon; Molina Jaque, Felipe A; Rodriguez-Hernandez, Ana; Arikan, Fuat; Lopez-Bermeo, Diego; Tomasello, Alejandro

2016-06-07

Multiple cerebral arteriovenous malformations (AVMs) are a rare occurrence usually associated with defined genetic disorders or a family history of cerebrovascular disease. The remaining cases cannot be associated to a genetic pathogenesis and are considered idiopathic. We report an extremely unusual case nor genetic neither idiopathic, but linked to an anatomical intracranial venous variation. The patient presented two independent frontal AVMs associated with rostral hypoplasia of the superior sagittal sinus. This anatomical variation may have induced frontal venous hypertension (VHT) triggering the development of the two AVMs. Throughout this intriguing case, we discuss the role of VHT in AVM development.

Clinical features and endodontic treatment of two-rooted mandibular canines: report of four cases.

PubMed

Stojanac, Igor; Premović, Milica; Drobac, Milan; Ramić, Bojana; Petrović, Ljubomir

2014-01-01

Predictable endodontic treatment depends on the dentist's knowledge about root canal morphology and its possible anatomic variations. The majority of mandibular canines have one root and root canal, but 15% may have two canals and a smaller number may have two distinct roots. The following clinical reports describe endodontic treatment of mandibular canines with two roots and two root canals. OUTLINE OF CASES Four clinical case reports are presented to exemplify anatomical variation in the human mandibular canine. Detailed analysis of the preoperative radiographs and careful examination of the pulp chamber floor detected the presence of two root canal orifices in all canines. Working length was determined with an electronic apex locator and biomechanical preparation was carried out by using engine driven BioRaCe Ni-Ti rotary instruments in a crown-down manner, followed by copious irrigation with 1% sodium hypochlorite. Definitive obturation was performed using cold lateral condensation with gutta-percha cones and Top Seal paste. The treatment outcome was evaluated using postoperative radiographs. Endodontists should be aware of anatomical variations of the treated teeth, and should never presume that canal systems are simple.

Anatomical variations within the deep posterior compartment of the leg and important clinical consequences.

PubMed

Hislop, M; Tierney, P

2004-09-01

The management of musculoskeletal conditions makes up a large part of a sports medicine practitioner's practice. A thorough knowledge of anatomy is an essential component of the armament necessary to decipher the large number of potential conditions that may confront these practitioners. To cloud the issue further, anatomical variations may be present, such as supernumerary muscles, thickened fascial bands or variant courses of nerves and blood vessels, which can themselves manifest as acute or chronic conditions that lead to significant morbidity or limitation of activity. There are a number of contentious areas within the literature surrounding the anatomy of the leg, particularly involving the deep posterior compartment. Conditions such as chronic exertional compartment syndrome, tibial periostitis (shin splints), peripheral nerve entrapment and tarsal tunnel syndrome may all be affected by subtle anatomical variations. This paper primarily focuses on the deep posterior compartment of the leg and uses the gross dissection of cadaveric specimens to describe definitively the anatomy of the deep posterior compartment. Variant fascial attachments of flexor digitorum longus are documented and potential clinical sequelae such as chronic exertional compartment syndrome and tarsal tunnel syndrome are discussed.

Anatomical Variations of the Circulus Arteriosus in Cadaveric Human Brains

PubMed Central

Gunnal, S. A.; Farooqui, M. S.; Wabale, R. N.

2014-01-01

Objective. Circulus arteriosus/circle of Willis (CW) is a polygonal anastomotic channel at the base of the brain which unites the internal carotid and vertebrobasilar system. It maintains the steady and constant supply to the brain. The variations of CW are seen often. The Aim of the present work is to find out the percentage of normal pattern of CW, and the frequency of variations of the CW and to study the morphological and morphometric aspects of all components of CW. Methods. Circulus arteriosus of 150 formalin preserved brains were dissected. Dimensions of all the components forming circles were measured. Variations of all the segments were noted and well photographed. The variations such as aplasia, hypoplasia, duplication, fenestrations, and difference in dimensions with opposite segments were noted. The data collected in the study was analyzed. Results. Twenty-one different types of CW were found in the present study. Normal and complete CW was found in 60%. CW with gross morphological variations was seen in 40%. Maximum variations were seen in the PCoA followed by the ACoA in 50% and 40%, respectively. Conclusion. As it confirms high percentage of variations, all surgical interventions should be preceded by angiography. Awareness of these anatomical variations is important in neurovascular procedures. PMID:24891951

Extrahepatic arteries of the human liver - anatomical variants and surgical relevancies.

PubMed

Németh, Károly; Deshpande, Rahul; Máthé, Zoltán; Szuák, András; Kiss, Mátyás; Korom, Csaba; Nemeskéri, Ágnes; Kóbori, László

2015-10-01

The purpose of our study was to investigate the anatomical variations of the extrahepatic arterial structures of the liver with particular attention to rare variations and their potential impact on liver surgery. A total of 50 human abdominal organ complexes were used to prepare corrosion casts. A multicomponent resin mixture was injected into the abdominal aorta. The portal vein was injected with a different colored resin in 16 cases. Digestion of soft tissues was achieved using cc. KOH solution at 60-65 °C. Extrahepatic arterial variations were classified according to Michels. All specimens underwent 3D volumetric CT reconstruction. Normal anatomy was seen in 42% of cases, and variants were seen in the other 58%. No Michels type VI or X variations were present; however, in 18% of cases the extrahepatic arterial anatomy did not fit into Michels' classification. We report four new extrahepatic arterial variations. In contrast to the available data, normal anatomy was found much less frequently, whereas the prevalence of unclassified arterial variations was higher. We detected four previously unknown variations. Our data may contribute to the reduction of complications during surgical and radiological interventions in the upper abdomen. © 2015 Steunstichting ESOT.

Development of a femoral template for computer-assisted tunnel placement in anatomical double-bundle ACL reconstruction.

PubMed

Luites, J W H; Wymenga, A B; Blankevoort, L; Kooloos, J M G; Verdonschot, N

2011-01-01

Femoral graft placement is an important factor in the success of anterior cruciate ligament (ACL) reconstruction. In addition to improving the accuracy of femoral tunnel placement, Computer Assisted Surgery (CAS) can be used to determine the anatomic location. This is achieved by using a 3D femoral template which indicates the position of the anatomical ACL center based on endoscopically measurable landmarks. This study describes the development and application of this method. The template is generated through statistical shape analysis of the ACL insertion, with respect to the anteromedial (AM) and posterolateral (PL) bundles. The ligament insertion data, together with the osteocartilage edge on the lateral notch, were mapped onto a cylinder fitted to the intercondylar notch surface (n = 33). Anatomic variation, in terms of standard variation of the positions of the ligament centers in the template, was within 2.2 mm. The resulting template was programmed in a computer-assisted navigation system for ACL replacement and its accuracy and precision were determined on 31 femora. It was found that with the navigation system the AM and PL tunnels could be positioned with an accuracy of 2.5 mm relative to the anatomic insertion centers; the precision was 2.4 mm. This system consists of a template that can easily be implemented in 3D computer navigation software. Requiring no preoperative images and planning, the system provides adequate accuracy and precision to position the entrance of the femoral tunnels for anatomical single- or double-bundle ACL reconstruction.

Effects of the Variation in Brain Tissue Mechanical Properties on the Intracranial Response of a 6-Year-Old Child.

PubMed

Cui, Shihai; Li, Haiyan; Li, Xiangnan; Ruan, Jesse

2015-01-01

Brain tissue mechanical properties are of importance to investigate child head injury using finite element (FE) method. However, these properties used in child head FE model normally vary in a large range in published literatures because of the insufficient child cadaver experiments. In this work, a head FE model with detailed anatomical structures is developed from the computed tomography (CT) data of a 6-year-old healthy child head. The effects of brain tissue mechanical properties on traumatic brain response are also analyzed by reconstruction of a head impact on engine hood according to Euro-NCAP testing regulation using FE method. The result showed that the variations of brain tissue mechanical parameters in linear viscoelastic constitutive model had different influences on the intracranial response. Furthermore, the opposite trend was obtained in the predicted shear stress and shear strain of brain tissues caused by the variations of mentioned parameters.

A review of the surface and internal anatomy of the caudal canal in children.

PubMed

Lees, David; Frawley, Geoff; Taghavi, Kiarash; Mirjalili, Seyed Ali

2014-08-01

The anatomy of the sacral hiatus and caudal canal is prone to significant variation, yet studies assessing this in the pediatric population remain limited. Awareness of the possible anatomical variations is critical to the safety and success of caudal epidural blocks, particularly when image guidance is not employed. This systematic review analyzes the available evidence on the clinical anatomy of the caudal canal in pediatric patients, emphasizing surface anatomy and internal anatomical variations. A literature search using three electronic databases and standard pediatric and anatomy reference texts was conducted yielding 24 primary and seven secondary English-language sources. Appreciating that our current landmark-guided approaches to the caudal canal are not well studied in the pediatric population is important for both clinicians and researchers. © 2014 John Wiley & Sons Ltd.

Anatomical Study of Variations in the Blood Supply of Kidneys

PubMed Central

Aristotle, Sharmila; Sundarapandian; Felicia, Christilda

2013-01-01

Background: Each kidney is supplied by a single renal artery and a single renal vein, which accounts for about 20% of the cardiac output. However, variations in the form of level of origin and arrangement of renal arteries are so frequent. Aim: The present study aimed to note the vascular anatomy of kidneys with respect to the variations in their origin, course and any aberrant vessels which were present. Materials and Methods: The study material comprised of 15 formalin fixed human cadavers. During routine abdominal dissection for undergraduate students, the kidneys were exposed and the blood supply, along with its variations, were noted. Results: The following anatomical findings are observed in this study: (i) Accessory renal arteries (ii) Presegmental arteries (iii) Upper polar arteries (iv) Lower polar arteries (v) Inferior suprarenal artery from accessory renal artery and (vi) Accessory renal vein. Conclusion: Awareness of the normal as well variational anatomy is mandatory for the surgeons, radiologists and urologists, for doing any uroradiological procedures or angiographic studies. Hence, this study will serve a useful guideline for the above mentioned procedures. PMID:24086837

Population of anatomically variable 4D XCAT adult phantoms for imaging research and optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Segars, W. P.; Bond, Jason; Frush, Jack

2013-04-15

Purpose: The authors previously developed the 4D extended cardiac-torso (XCAT) phantom for multimodality imaging research. The XCAT consisted of highly detailed whole-body models for the standard male and female adult, including the cardiac and respiratory motions. In this work, the authors extend the XCAT beyond these reference anatomies by developing a series of anatomically variable 4D XCAT adult phantoms for imaging research, the first library of 4D computational phantoms. Methods: The initial anatomy of each phantom was based on chest-abdomen-pelvis computed tomography data from normal patients obtained from the Duke University database. The major organs and structures for each phantommore » were segmented from the corresponding data and defined using nonuniform rational B-spline surfaces. To complete the body, the authors manually added on the head, arms, and legs using the original XCAT adult male and female anatomies. The structures were scaled to best match the age and anatomy of the patient. A multichannel large deformation diffeomorphic metric mapping algorithm was then used to calculate the transform from the template XCAT phantom (male or female) to the target patient model. The transform was applied to the template XCAT to fill in any unsegmented structures within the target phantom and to implement the 4D cardiac and respiratory models in the new anatomy. Each new phantom was refined by checking for anatomical accuracy via inspection of the models. Results: Using these methods, the authors created a series of computerized phantoms with thousands of anatomical structures and modeling cardiac and respiratory motions. The database consists of 58 (35 male and 23 female) anatomically variable phantoms in total. Like the original XCAT, these phantoms can be combined with existing simulation packages to simulate realistic imaging data. Each new phantom contains parameterized models for the anatomy and the cardiac and respiratory motions and can, therefore, serve as a jumping point from which to create an unlimited number of 3D and 4D variations for imaging research. Conclusions: A population of phantoms that includes a range of anatomical variations representative of the public at large is needed to more closely mimic a clinical study or trial. The series of anatomically variable phantoms developed in this work provide a valuable resource for investigating 3D and 4D imaging devices and the effects of anatomy and motion in imaging. Combined with Monte Carlo simulation programs, the phantoms also provide a valuable tool to investigate patient-specific dose and image quality, and optimization for adults undergoing imaging procedures.« less

Learning-based stochastic object models for use in optimizing imaging systems

NASA Astrophysics Data System (ADS)

Dolly, Steven R.; Anastasio, Mark A.; Yu, Lifeng; Li, Hua

2017-03-01

It is widely known that the optimization of imaging systems based on objective, or task-based, measures of image quality via computer-simulation requires use of a stochastic object model (SOM). However, the development of computationally tractable SOMs that can accurately model the statistical variations in anatomy within a specified ensemble of patients remains a challenging task. Because they are established by use of image data corresponding a single patient, previously reported numerical anatomical models lack of the ability to accurately model inter- patient variations in anatomy. In certain applications, however, databases of high-quality volumetric images are available that can facilitate this task. In this work, a novel and tractable methodology for learning a SOM from a set of volumetric training images is developed. The proposed method is based upon geometric attribute distribution (GAD) models, which characterize the inter-structural centroid variations and the intra-structural shape variations of each individual anatomical structure. The GAD models are scalable and deformable, and constrained by their respective principal attribute variations learned from training data. By use of the GAD models, random organ shapes and positions can be generated and integrated to form an anatomical phantom. The randomness in organ shape and position will reflect the variability of anatomy present in the training data. To demonstrate the methodology, a SOM corresponding to the pelvis of an adult male was computed and a corresponding ensemble of phantoms was created. Additionally, computer-simulated X-ray projection images corresponding to the phantoms were computed, from which tomographic images were reconstructed.

Single-Blinded Prospective Implementation of a Preoperative Imaging Checklist for Endoscopic Sinus Surgery.

PubMed

Error, Marc; Ashby, Shaelene; Orlandi, Richard R; Alt, Jeremiah A

2018-01-01

Objective To determine if the introduction of a systematic preoperative sinus computed tomography (CT) checklist improves identification of critical anatomic variations in sinus anatomy among patients undergoing endoscopic sinus surgery. Study Design Single-blinded prospective cohort study. Setting Tertiary care hospital. Subjects and Methods Otolaryngology residents were asked to identify critical surgical sinus anatomy on preoperative CT scans before and after introduction of a systematic approach to reviewing sinus CT scans. The percentage of correctly identified structures was documented and compared with a 2-sample t test. Results A total of 57 scans were reviewed: 28 preimplementation and 29 postimplementation. Implementation of the sinus CT checklist improved identification of critical sinus anatomy from 24% to 84% correct ( P < .001). All residents, junior and senior, demonstrated significant improvement in identification of sinus anatomic variants, including those not directly included in the systematic review implemented. Conclusion The implementation of a preoperative endoscopic sinus surgery radiographic checklist improves identification of critical anatomic sinus variations in a training population.

Anatomical Variability in the Termination of the Basilar Artery in the Human Cadaveric Brain.

PubMed

Gunnal, Sandhya; Farooqui, Mujeebuddin; Wabale, Rajendra

2015-01-01

The basilar artery (BA) is the prominent median vessel of the vertebrobasilar circulation and usually terminates into two posterior cerebral arteries forming the posterior angle of the Circle of Willis (CW). To tackle different variations of CW, basilar artery acts as a guideline for neuroradiologists and neurosurgeons. Basilar termination is the most frequent site of aneurysm. Abnormalities at the site of termination may compress the oculomotor nerve. Variations at the termination may complicate surgeries at the base of brain. The present study aims to add to the knowledge regarding the termination pattern of the BA. 170 BA terminations were studied. Morphological variations in the termination pattern were noted. Frequency of variations in termination patterns was recorded. Dimensions of BA were measured. Data were analyzed. Morphological variations in termination were seen in 17.64%. Bifurcation, Trifurcation, Quadrifurcation, Pentafurcation and Nonfurcation of BA was seen in 82.35%, 5.29%, 5.88%, 3.52% and 2.94% respectively. BA associated with aneurysm and Fenestration was seen in 3.52% and 1.17% respectively. Mean length and diameter of BA was 30.27 mm and 4.8 mm respectively. Awareness of these anatomical variations in termination patterns of BA is important in neurovascular procedures.

Three rooted, four canalled mandibular first molar (Radix Entomolaris).

PubMed

Parolia, Abhishek; Kundabala, M; Thomas, M S; Mohan, M; Joshi, N

2009-01-01

A mandibular first molar with two distal roots is an interesting example of anatomic variation. This paper describes case reports of mandibular first molar with three roots (one mesial and two distal) and four canals (two in mesial and one in each distobuccal and distolingual root). The canals were shaped with protaper rotary files and irrigated with 5.25% sodium hyochlorite, 0.2 %w/v of chlorhexidine gluconate and normal saline as the fi nal irrigant. The canals were then obturated with gutta- percha and AH plus sealer. These case reports show an anatomic variation of internal morphology of the tooth and points out the importance of searching for additional canals.

Leaf anatomy does not explain apparent short-term responses of mesophyll conductance to light and CO2 in tobacco.

PubMed

Carriquí, Marc; Douthe, Cyril; Molins, Arántzazu; Flexas, Jaume

2018-05-10

Mesophyll conductance to CO 2 (g m ), a key photosynthetic trait, is strongly constrained by leaf anatomy. Leaf anatomical parameters such as cell wall thickness and chloroplast area exposed to the mesophyll intercellular airspace have been demonstrated to determine g m in species with diverging phylogeny, leaf structure and ontogeny. However, the potential implication of leaf anatomy, especially chloroplast movement, on the short-term response of g m to rapid changes (i.e. seconds to minutes) under different environmental conditions (CO 2 , light or temperature) has not been examined. The aim of this study was to determine whether the observed rapid variations of g m in response to variations of light and CO 2 could be explained by changes in any leaf anatomical arrangements. When compared to high light and ambient CO 2 , the values of g m estimated by chlorophyll fluorescence decreased under high CO 2 and increased at low CO 2 , while it decreased with decreasing light. Nevertheless, no changes in anatomical parameters, including chloroplast distribution, were found. Hence, the g m estimated by analytical models based on anatomical parameters was constant under varying light and CO 2 . Considering this discrepancy between anatomy and chlorophyll fluorescence estimates, it is concluded that apparent fast g m variations should be due to artifacts in its estimation and/or to changes in the biochemical components acting on diffusional properties of the leaf (e.g. aquaporins and carbonic anhydrase). This article is protected by copyright. All rights reserved.

[Anatomy of the liver: what you need to know].

PubMed

Lafortune, M; Denys, A; Sauvanet, A; Schmidt, S

2007-01-01

A precise knowledge of arterial, portal, hepatic and biliary anatomical variations is mandatory when a liver intervention is planned. However, only certain variations must be searched when a precise intervention is planned. The basic liver anatomy as well as the most relevant malformations will be precised.

Herd outbreak of bovine tuberculosis illustrates that route of infection correlates with anatomic distribution of lesions in cattle and cats.

PubMed

Fitzgerald, Scott D; Hollinger, Charlotte; Mullaney, Thomas P; Bruning-Fann, Colleen S; Tilden, John; Smith, Rick; Averill, James; Kaneene, John B

2016-03-01

An outbreak of bovine tuberculosis (TB) in a Michigan dairy herd resulted in quarantine, depopulation, pathology, and epidemiologic investigations. This herd, compared to other TB-infected herds in Michigan, was unusual in the long-term feeding of waste milk to its replacement calves. The herd had 80 cattle with positive results on caudal fold test or gamma interferon testing, which were reclassified as suspects because the herd had never been known to be tuberculous previously. Autopsy revealed striking variation in the anatomic distribution of gross anatomic lesions, microscopic lesions, and culture-positive lymph nodes between the adult cattle, the calves, and the domestic cats present on the farm. Adult cattle had lesions and culture-positive lymph nodes predominantly within the thoracic lymph nodes, whereas cats had 50% of their lesions and culture-positive lymph nodes in their abdomens, and 50% of positive calves had culture-positive lymph nodes in their abdomens. This difference in anatomic distribution correlated with the likely routes of infection, which are believed to be by direct airborne transmission in adult cattle and indirect ingestion of contaminated milk in both calves and cats. Although TB literature over the past 100-plus years states that the route of infection may manifest itself in differences in lesion anatomic distribution, our team has been working with TB for over 20 years, and we have never encountered such striking variation between different groups of animals on the same farm. © 2016 The Author(s).

Retro-aortic left renal vein--an anatomic variation description and review of literature.

PubMed

Suma, H Yekappa; Roopa, Kulkarni

2011-01-01

This study reports the presence of a retro-aortic renal vein on the left side draining into the inferior vena cava. This variation was observed during routine dissection in a female cadaver aged about 55 years. This variation is of importance because of its implications in renal transplantation, renal surgery, vascular surgery, uroradiology and gonadal surgeries. The knowledge of such variations can help the clinicians for its recognition and protection.

Impact of anatomical parameters on optical coherence tomography retinal nerve fiber layer thickness abnormality patterns

NASA Astrophysics Data System (ADS)

Baniasadi, Neda; Wang, Mengyu; Wang, Hui; Jin, Qingying; Mahd, Mufeed; Elze, Tobias

2017-02-01

Purpose: To evaluate the effects of four anatomical parameters (angle between superior and inferior temporal retinal arteries [inter-artery angle, IAA], optic disc [OD] rotation, retinal curvature, and central retinal vessel trunk entry point location [CRVTL]) on retinal nerve fiber layer thickness (RNFLT) abnormality marks by OCT machines. Methods: Cirrus OCT circumpapillary RNFLT measurements and Humphrey visual fields (HVF 24-2) of 421 patients from a large glaucoma clinic were included. Ellipses were fitted to the OD borders. Ellipse rotation relative to the vertical axis defined OD rotation. CRVTL was manually marked on the horizontal axis of the ellipse on the OCT fundus image. IAA was calculated between manually marked retinal artery locations at the 1.73mm radius around OD. Retinal curvature was determined by the inner limiting membrane on the horizontal B-scan closest to the OD center. For each location on the circumpapillary scanning area, logistic regression was used to determine if each of the four parameters had a significant impact on RNFLT abnormality marks independent of disease severity. The results are presented on spatial maps of the entire scanning area. Results: Variations in IAA significantly influenced abnormality marks on 38.8% of the total scanning area, followed by CRVTL (19.2%) and retinal curvature (18.7%). The effect of OD rotation was negligible (<1%). Conclusions: A natural variation in IAA, retinal curvature, and CRVTL can affect OCT abnormality ratings, which may bias clinical diagnosis. Our spatial maps may help OCT manufacturers to introduce location specific norms to ensure that abnormality marks indicate ocular disease instead of variations in eye anatomy.

An investigation of the trade-off between the count level and image quality in myocardial perfusion SPECT using simulated images: the effects of statistical noise and object variability on defect detectability

NASA Astrophysics Data System (ADS)

He, Xin; Links, Jonathan M.; Frey, Eric C.

2010-09-01

Quantum noise as well as anatomic and uptake variability in patient populations limits observer performance on a defect detection task in myocardial perfusion SPECT (MPS). The goal of this study was to investigate the relative importance of these two effects by varying acquisition time, which determines the count level, and assessing the change in performance on a myocardial perfusion (MP) defect detection task using both mathematical and human observers. We generated ten sets of projections of a simulated patient population with count levels ranging from 1/128 to around 15 times a typical clinical count level to simulate different levels of quantum noise. For the simulated population we modeled variations in patient, heart and defect size, heart orientation and shape, defect location, organ uptake ratio, etc. The projection data were reconstructed using the OS-EM algorithm with no compensation or with attenuation, detector response and scatter compensation (ADS). The images were then post-filtered and reoriented to generate short-axis slices. A channelized Hotelling observer (CHO) was applied to the short-axis images, and the area under the receiver operating characteristics (ROC) curve (AUC) was computed. For each noise level and reconstruction method, we optimized the number of iterations and cutoff frequencies of the Butterworth filter to maximize the AUC. Using the images obtained with the optimal iteration and cutoff frequency and ADS compensation, we performed human observer studies for four count levels to validate the CHO results. Both CHO and human observer studies demonstrated that observer performance was dependent on the relative magnitude of the quantum noise and the patient variation. When the count level was high, the patient variation dominated, and the AUC increased very slowly with changes in the count level for the same level of anatomic variability. When the count level was low, however, quantum noise dominated, and changes in the count level resulted in large changes in the AUC. This behavior agreed with a theoretical expression for the AUC as a function of quantum and anatomical noise levels. The results of this study demonstrate the importance of the tradeoff between anatomical and quantum noise in determining observer performance. For myocardial perfusion imaging, it indicates that, at current clinical count levels, there is some room to reduce acquisition time or injected activity without substantially degrading performance on myocardial perfusion defect detection.

Variation compensation and analysis on diaphragm curvature analysis for emphysema quantification on whole lung CT scans

NASA Astrophysics Data System (ADS)

Keller, Brad M.; Reeves, Anthony P.; Barr, R. Graham; Yankelevitz, David F.; Henschke, Claudia I.

2010-03-01

CT scans allow for the quantitative evaluation of the anatomical bases of emphysema. Recently, a non-density based geometric measurement of lung diagphragm curvature has been proposed as a method for the quantification of emphysema from CT. This work analyzes variability of diaphragm curvature and evaluates the effectiveness of a compensation methodology for the reduction of this variability as compared to emphysema index. Using a dataset of 43 scan-pairs with less than a 100 day time-interval between scans, we find that the diaphragm curvature had a trend towards lower overall variability over emphysema index (95% CI:-9.7 to + 14.7 vs. -15.8 to +12.0), and that the variation of both measures was reduced after compensation. We conclude that the variation of the new measure can be considered comparable to the established measure and the compensation can reduce the apparent variation of quantitative measures successfully.

TOPICAL REVIEW: Anatomical imaging for radiotherapy

NASA Astrophysics Data System (ADS)

Evans, Philip M.

2008-06-01

The goal of radiation therapy is to achieve maximal therapeutic benefit expressed in terms of a high probability of local control of disease with minimal side effects. Physically this often equates to the delivery of a high dose of radiation to the tumour or target region whilst maintaining an acceptably low dose to other tissues, particularly those adjacent to the target. Techniques such as intensity modulated radiotherapy (IMRT), stereotactic radiosurgery and computer planned brachytherapy provide the means to calculate the radiation dose delivery to achieve the desired dose distribution. Imaging is an essential tool in all state of the art planning and delivery techniques: (i) to enable planning of the desired treatment, (ii) to verify the treatment is delivered as planned and (iii) to follow-up treatment outcome to monitor that the treatment has had the desired effect. Clinical imaging techniques can be loosely classified into anatomic methods which measure the basic physical characteristics of tissue such as their density and biological imaging techniques which measure functional characteristics such as metabolism. In this review we consider anatomical imaging techniques. Biological imaging is considered in another article. Anatomical imaging is generally used for goals (i) and (ii) above. Computed tomography (CT) has been the mainstay of anatomical treatment planning for many years, enabling some delineation of soft tissue as well as radiation attenuation estimation for dose prediction. Magnetic resonance imaging is fast becoming widespread alongside CT, enabling superior soft-tissue visualization. Traditionally scanning for treatment planning has relied on the use of a single snapshot scan. Recent years have seen the development of techniques such as 4D CT and adaptive radiotherapy (ART). In 4D CT raw data are encoded with phase information and reconstructed to yield a set of scans detailing motion through the breathing, or cardiac, cycle. In ART a set of scans is taken on different days. Both allow planning to account for variability intrinsic to the patient. Treatment verification has been carried out using a variety of technologies including: MV portal imaging, kV portal/fluoroscopy, MVCT, conebeam kVCT, ultrasound and optical surface imaging. The various methods have their pros and cons. The four x-ray methods involve an extra radiation dose to normal tissue. The portal methods may not generally be used to visualize soft tissue, consequently they are often used in conjunction with implanted fiducial markers. The two CT-based methods allow measurement of inter-fraction variation only. Ultrasound allows soft-tissue measurement with zero dose but requires skilled interpretation, and there is evidence of systematic differences between ultrasound and other data sources, perhaps due to the effects of the probe pressure. Optical imaging also involves zero dose but requires good correlation between the target and the external measurement and thus is often used in conjunction with an x-ray method. The use of anatomical imaging in radiotherapy allows treatment uncertainties to be determined. These include errors between the mean position at treatment and that at planning (the systematic error) and the day-to-day variation in treatment set-up (the random error). Positional variations may also be categorized in terms of inter- and intra-fraction errors. Various empirical treatment margin formulae and intervention approaches exist to determine the optimum strategies for treatment in the presence of these known errors. Other methods exist to try to minimize error margins drastically including the currently available breath-hold techniques and the tracking methods which are largely in development. This paper will review anatomical imaging techniques in radiotherapy and how they are used to boost the therapeutic benefit of the treatment.

SU-C-210-05: Evaluation of Robustness: Dosimetric Effects of Anatomical Changes During Fractionated Radiation Treatment of Pancreatic Cancer Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Horst, A van der; Houweling, A C; Bijveld, M M C

2015-06-15

Purpose: Pancreatic tumors show large interfractional position variations. In addition, changes in gastrointestinal air volume and body contour take place during treatment. We aim to investigate the robustness of the clinical treatment plans by quantifying the dosimetric effects of these anatomical changes. Methods: Calculations were performed for up to now 3 pancreatic cancer patients who had intratumoral fiducials for daily CBCT-based positioning during their 3-week treatment. For each patient, deformable image registration of the planning CT was used to assign Hounsfield Units to each of the 13—15 CBCTs; air volumes and body contour were copied from CBCT. The clinical treatmentmore » plan was used (CTV-PTV margin = 10 mm; 36Gy; 10MV; 1 arc VMAT). Fraction dose distributions were calculated and accumulated. The V95% of the clinical target volume (CTV) and planning target volume (PTV) were analyzed, as well as the dose to stomach, duodenum and liver. Dose accumulation was done for patient positioning based on the fiducials (as clinically used) as well as for positioning based on bony anatomy. Results: For all three patients, the V95% of the CTV remained 100%, for both fiducial- and bony anatomy-based positioning. For fiducial-based positioning, dose to duodenum en stomach showed no discernable differences with planned dose. For bony anatomy-based positioning, the PTV V95% of the patient with the largest systematic difference in tumor position (patient 1) decreased to 85%; the liver Dmax increased from 33.5Gy (planned) to 35.5Gy. Conclusion: When using intratumoral fiducials, CTV dose coverage was only mildly affected by the daily anatomical changes. When using bony anatomy for patient positioning, we found a decline in PTV dose coverage due to the interfractional tumor position variations. Photon irradiation treatment plans for pancreatic tumors are robust to variations in body contour and gastrointestinal gas, but the use of fiducial-based daily position verification is imperative. This work was supported by the foundation Bergh in het Zadel through the Dutch Cancer Society (KWF Kankerbestrijding) project No. UVA 2011-5271.« less

Variations of response time in a selective attention task are linked to variations of functional connectivity in the attentional network.

PubMed

Prado, Jérôme; Carp, Joshua; Weissman, Daniel H

2011-01-01

Although variations of response time (RT) within a particular experimental condition are typically ignored, they may sometimes reflect meaningful changes in the efficiency of cognitive and neural processes. In the present study, we investigated whether trial-by-trial variations of response time (RT) in a cross-modal selective attention task were associated with variations of functional connectivity between brain regions that are thought to underlie attention. Sixteen healthy young adults performed an audiovisual selective attention task, which involved attending to a relevant visual letter while ignoring an irrelevant auditory letter, as we recorded their brain activity using functional magnetic resonance imaging (fMRI). In line with predictions, variations of RT were associated with variations of functional connectivity between the anterior cingulate cortex and various other brain regions that are posited to underlie attentional control, such as the right dorsolateral prefrontal cortex and bilateral regions of the posterior parietal cortex. They were also linked to variations of functional connectivity between anatomically early and anatomically late regions of the relevant-modality visual cortex whose communication is thought to be modulated by attentional control processes. By revealing that variations of RT in a selective attention task are linked to variations of functional connectivity in the attentional network, the present findings suggest that variations of attention may contribute to trial-by-trial fluctuations of behavioral performance. Copyright © 2010 Elsevier Inc. All rights reserved.

Geographical genetic structuring and phenotypic variation in the Vellozia hirsuta (Velloziaceae) ochlospecies complex.

PubMed

Barbosa, Ariane R; Fiorini, Cecília F; Silva-Pereira, Viviane; Mello-Silva, Renato; Borba, Eduardo L

2012-09-01

Vellozia hirsuta forms a complex presenting wide morphological and anatomical variation, resulting in five specific names and 14 morpho-anatomical patterns occurring in disjunct populations. We carried out a phylogeographical study to investigate the existence of correlation among the genetic and morphological patterns within this complex, and to determine whether it is composed of various species or should be treated as an ochlospecies, a species having widely polymorphic and weakly polytypic complex variation, with morphological characteristics varying independently. We carried out phylogeographical analyses using cpDNA rpl32F-trnL intergenic region. We found 20 haplotypes in 23 populations sampled. The populations are genetically structured (Φ(ST) = 0.818) into four phylogeographical groups demonstrating geographical structuring but with no correlation with morpho-anatomical patterns. Our analyses do not support recognizing any of the species now synonymized under Vellozia hirsuta. The northern populations were the most genetically differentiated and could be considered a distinct taxon, as they are also morphologically different. It is recommended that Vellozia hirsuta be considered a single enormously variable species. The patterns of variation within V. hirsuta probably are related to climatic changes that occurred during the Pleistocene Epoch in tropical Brazil when reductions in forest cover favored the expansion of V. hirsuta populations into extensive lowland areas. The expansion of forest cover at the end of the glaciations would have again restricted the occurrence of campos rupestres vegetation to high elevations, which constitute the current centers of diversity of this species.

Take away body parts! An investigation into the use of 3D-printed anatomical models in undergraduate anatomy education.

PubMed

Smith, Claire F; Tollemache, Nicholas; Covill, Derek; Johnston, Malcolm

2018-01-01

Understanding the three-dimensional (3D) nature of the human form is imperative for effective medical practice and the emergence of 3D printing creates numerous opportunities to enhance aspects of medical and healthcare training. A recently deceased, un-embalmed donor was scanned through high-resolution computed tomography. The scan data underwent segmentation and post-processing and a range of 3D-printed anatomical models were produced. A four-stage mixed-methods study was conducted to evaluate the educational value of the models in a medical program. (1) A quantitative pre/post-test to assess change in learner knowledge following 3D-printed model usage in a small group tutorial; (2) student focus group (3) a qualitative student questionnaire regarding personal student model usage (4) teaching faculty evaluation. The use of 3D-printed models in small-group anatomy teaching session resulted in a significant increase in knowledge (P = 0.0001) when compared to didactic 2D-image based teaching methods. Student focus groups yielded six key themes regarding the use of 3D-printed anatomical models: model properties, teaching integration, resource integration, assessment, clinical imaging, and pathology and anatomical variation. Questionnaires detailed how students used the models in the home environment and integrated them with anatomical learning resources such as textbooks and anatomy lectures. In conclusion, 3D-printed anatomical models can be successfully produced from the CT data set of a recently deceased donor. These models can be used in anatomy education as a teaching tool in their own right, as well as a method for augmenting the curriculum and complementing established learning modalities, such as dissection-based teaching. Anat Sci Educ 11: 44-53. © 2017 American Association of Anatomists. © 2017 American Association of Anatomists.

[Morphogenesis in formative process in vitro from Rehmannia glutinosa].

PubMed

Xue, Jian-ping; Zhang, Ai-min; Liu, Jun; Xu, Xue-feng

2004-01-01

To study the morphogenesis in formative process of tuberous root in vitro from Rehmannia glutinosa and compare the anatomical shape of tuberous root with nature term R. glutinosa. Tuberous roots of different vegetal phase were cut and dyed, then made into paraffin cuts and observed microscope. In anatomical shape, nature R. glutinosa and tuberous root were the same, which showed that no structural variation occurred in tuberous root induced process.

Analysis of anatomic periarticular tibial plate fit on normal adults.

PubMed

Goyal, Kanu S; Skalak, Anthony S; Marcus, Randall E; Vallier, Heather A; Cooperman, Daniel R

2007-08-01

Implant manufacturers are producing anatomically contoured periarticular plates to improve the treatment of proximal tibia fractures. We assessed the accuracy of the designation anatomic. We applied eight-hole medial and lateral anatomically contoured periarticular plates to 101 cadaveric tibiae. The tibiae and the plate fits were mapped, quantified, and analyzed using a MicroScribe G2LX digitizer, Rhinoceros software, and MATLAB software. By corresponding the clinical appearance of good fit with our digital findings, we created numerical criteria for plate fit in three planes: coronal (volume of free space between the plate and bone), sagittal (alignment with the tibial plateau and shaft), and axial (match in curvature between the proximal horizontal part of the plate and the tibial plateau). An anatomic fit should mirror the shape of the tibia in all three planes, and only four medial and four lateral plate fits qualified. Recognizing and understanding the substantial variations in fit that exist between anatomically contoured plates and the tibia may help lead to a more stable fixation and prevent malreduction of the fracture and/or soft tissue impingement.

The tarsal-metatarsal complex of caviomorph rodents: Anatomy and functional-adaptive analysis.

PubMed

Candela, Adriana M; Muñoz, Nahuel A; García-Esponda, César M

2017-06-01

Caviomorph rodents represent a major adaptive radiation of Neotropical mammals. They occupy a variety of ecological niches, which is also reflected in their wide array of locomotor behaviors. It is expected that this radiation would be mirrored by an equivalent disparity of tarsal-metatarsal morphology. Here, the tarsal-metatarsal complex of Erethizontidae, Cuniculidae, Dasyproctidae, Caviidae, Chinchillidae, Octodontidae, Ctenomyidae, and Echimyidae was examined, in order to evaluate its anatomical variation and functional-adaptive relevance in relation to locomotor behaviors. A qualitative study in functional morphology and a geometric morphometric analysis were performed. We recognized two distinct tarsal-metatarsal patterns that represent the extremes of anatomical variation in the foot. The first, typically present in arboreal species, is characterized by features that facilitate movements at different levels of the tarsal-metatarsal complex. The second pattern, typically present in cursorial caviomorphs, has a set of features that act to stabilize the joints, improve the interlocking of the tarsal bones, and restrict movements to the parasagittal plane. The morphological disparity recognized in this study seems to result from specific locomotor adaptations to climb, dig, run, jump and swim, as well as phylogenetic effects within and among the groups studies. © 2017 Wiley Periodicals, Inc.

Determinants of the electric field during transcranial direct current stimulation.

PubMed

Opitz, Alexander; Paulus, Walter; Will, Susanne; Antunes, Andre; Thielscher, Axel

2015-04-01

Transcranial direct current stimulation (tDCS) causes a complex spatial distribution of the electric current flow in the head which hampers the accurate localization of the stimulated brain areas. In this study we show how various anatomical features systematically shape the electric field distribution in the brain during tDCS. We constructed anatomically realistic finite element (FEM) models of two individual heads including conductivity anisotropy and different skull layers. We simulated a widely employed electrode montage to induce motor cortex plasticity and moved the stimulating electrode over the motor cortex in small steps to examine the resulting changes of the electric field distribution in the underlying cortex. We examined the effect of skull thickness and composition on the passing currents showing that thinner skull regions lead to higher electric field strengths. This effect is counteracted by a larger proportion of higher conducting spongy bone in thicker regions leading to a more homogenous current over the skull. Using a multiple regression model we could identify key factors that determine the field distribution to a significant extent, namely the thicknesses of the cerebrospinal fluid and the skull, the gyral depth and the distance to the anode and cathode. These factors account for up to 50% of the spatial variation of the electric field strength. Further, we demonstrate that individual anatomical factors can lead to stimulation "hotspots" which are partly resistant to electrode positioning. Our results give valuable novel insights in the biophysical foundation of tDCS and highlight the importance to account for individual anatomical factors when choosing an electrode montage. Copyright © 2015 Elsevier Inc. All rights reserved.

The mechanism of transient myopia induced by sulfonamide therapy.

PubMed

Bovino, J A; Marcus, D F

1982-07-01

We performed acute and convalescent A-scan echographic ocular measurements documenting the anterior chamber depth, lens thickness, and axial length of a patient with acute transient sulfamethoxazole-induced myopia. Shallowing of the anterior chamber, independent of changes in the thickness of the lens, was the only anatomic variation found that could explain the myopia. Swelling of the ciliary body, with forward movement of the lens-iris diaphragm, could produce this transient anatomic change.

A review of simulation platforms in surgery of the temporal bone.

PubMed

Bhutta, M F

2016-10-01

Surgery of the temporal bone is a high-risk activity in an anatomically complex area. Simulation enables rehearsal of such surgery. The traditional simulation platform is the cadaveric temporal bone, but in recent years other simulation platforms have been created, including plastic and virtual reality platforms. To undertake a review of simulation platforms for temporal bone surgery, specifically assessing their educational value in terms of validity and in enabling transition to surgery. Systematic qualitative review. Search of the Pubmed, CINAHL, BEI and ERIC databases. Assessment of reported outcomes in terms of educational value. A total of 49 articles were included, covering cadaveric, animal, plastic and virtual simulation platforms. Cadaveric simulation is highly rated as an educational tool, but there may be a ceiling effect on educational outcomes after drilling 8-10 temporal bones. Animal models show significant anatomical variation from man. Plastic temporal bone models offer much potential, but at present lack sufficient anatomical or haptic validity. Similarly, virtual reality platforms lack sufficient anatomical or haptic validity, but with technological improvements they are advancing rapidly. At present, cadaveric simulation remains the best platform for training in temporal bone surgery. Technological advances enabling improved materials or modelling mean that in the future plastic or virtual platforms may become comparable to cadaveric platforms, and also offer additional functionality including patient-specific simulation from CT data. © 2015 John Wiley & Sons Ltd.

A micro-computed tomography study of the negotiation and anatomical feature in apical root canal of mandibular molars.

PubMed

Min, Yi; Ma, Jing-Zhi; Shen, Ya; Cheung, Gary Shun-Pan; Gao, Yuan

2016-11-01

The aim of this study was to investigate the clinical negotiation of various apical anatomic features of the mandibular first molars in a Chinese population using micro-computed tomography (micro-CT). A total of 152 mandibular first molars were scanned with micro-CT at 30 µm resolution. The apical 5 mm of root canal (ARC) was reconstructed three dimensionally and classified. Subsequently, the access cavity was prepared with the ARC anatomy blinded to the operator. The ARC was negotiated with a size 10 K file with or without precurve. Information on the ability to obtain a reproducible glide path was recorded. The anatomical classification of ARC was Type I with 68.45% in mandibular first molars. The negotiation result of ARC with Category i was 387 canals (74.00%). With a bent negotiating file, 96 canals were negotiated, including 88 reproducible glide paths (Category ii) and 8 irregular glide paths (Category iii). About 7.65% canals could not be negotiated with patency successfully (Category iv). The statistical analyze shown the anatomic feature of ARC had effect on the negotiation of ARC (p < 0.05). In conclusion, ARC anatomic variations had a strong potential impact on the negotiation. The category of negotiation in ARC would be helpful in the using of NiTi rotary instruments. Negotiation of ARC to the working length with patency should be careful and skillful because of the complexities of ARC. SCANNING 38:819-824, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Modeling and segmentation of intra-cochlear anatomy in conventional CT

NASA Astrophysics Data System (ADS)

Noble, Jack H.; Rutherford, Robert B.; Labadie, Robert F.; Majdani, Omid; Dawant, Benoit M.

2010-03-01

Cochlear implant surgery is a procedure performed to treat profound hearing loss. Since the cochlea is not visible in surgery, the physician uses anatomical landmarks to estimate the pose of the cochlea. Research has indicated that implanting the electrode in a particular cavity of the cochlea, the scala tympani, results in better hearing restoration. The success of the scala tympani implantation is largely dependent on the point of entry and angle of electrode insertion. Errors can occur due to the imprecise nature of landmark-based, manual navigation as well as inter-patient variations between scala tympani and the anatomical landmarks. In this work, we use point distribution models of the intra-cochlear anatomy to study the inter-patient variations between the cochlea and the typical anatomic landmarks, and we implement an active shape model technique to automatically localize intra-cochlear anatomy in conventional CT images, where intra-cochlear structures are not visible. This fully automatic segmentation could aid the surgeon to choose the point of entry and angle of approach to maximize the likelihood of scala tympani insertion, resulting in more substantial hearing restoration.

Effects of the Variation in Brain Tissue Mechanical Properties on the Intracranial Response of a 6-Year-Old Child

PubMed Central

Cui, Shihai; Li, Haiyan; Li, Xiangnan; Ruan, Jesse

2015-01-01

Brain tissue mechanical properties are of importance to investigate child head injury using finite element (FE) method. However, these properties used in child head FE model normally vary in a large range in published literatures because of the insufficient child cadaver experiments. In this work, a head FE model with detailed anatomical structures is developed from the computed tomography (CT) data of a 6-year-old healthy child head. The effects of brain tissue mechanical properties on traumatic brain response are also analyzed by reconstruction of a head impact on engine hood according to Euro-NCAP testing regulation using FE method. The result showed that the variations of brain tissue mechanical parameters in linear viscoelastic constitutive model had different influences on the intracranial response. Furthermore, the opposite trend was obtained in the predicted shear stress and shear strain of brain tissues caused by the variations of mentioned parameters. PMID:26495031

Anatomical variation of the Dorsalis pedis artery in a South African population - A Cadaveric Study.

PubMed

Ntuli, S; Nalla, S; Kiter, A

2018-05-10

The dorsalis pedis artery is responsible for blood supply to the dorsal aspect of the foot and is vital in the clinical assessment of the arterial supply thereof. Clinical assessment should consider anatomical variations of dorsalis pedis artery. Clearly, a thorough understanding of the potential variations of the vasculature in the area is important for a precise clinical assessment of arterial supply to the foot. The aim of this study was to investigate the different branching patterns of the dorsalis pedis artery that exist in a South African population. A Cadaveric study in which a total of 33 dissected lower limbs (27 adult cadavers and 6 partial wet lower limb specimens) of a South African population sample were studied. The course and branching pattern of the dorsalis pedis artery were photographed and documented. Nine variations of the dorsalis pedis artery were recorded, with the standard branching pattern being the most common with an incidence of 36.36% and a completely absent dorsalis pedis artery variation was noted in 6.06% of the sample. Nine variations of the arterial anatomy of the dorsalis pedis artery were identified in this current study. Each of these may possibly alter the location or strength of the dorsalis pedis pulse affecting clinical assessment outcomes. Knowledge of dorsalis pedis variations may be useful to clinicians when making clinical decisions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Anthropometric Study of the Piriformis Muscle and Sciatic Nerve: A Morphological Analysis in a Polish Population

PubMed Central

Haładaj, Robert; Pingot, Mariusz; Polguj, Michał; Wysiadecki, Grzegorz; Topol, Mirosław

2015-01-01

Background The aim of this study was to determine relationships between piriformis muscle (PM) and sciatic nerve (SN) with reference to sex and anatomical variations. Material/Methods Deep dissection of the gluteal region was performed on 30 randomized, formalin-fixed human lower limbs of adults of both sexes of the Polish population. Anthropometric measurements were taken and then statistically analyzed. Results The conducted research revealed that, apart from the typical structure of the piriformis muscle, the most common variation was division of the piriformis muscle into two heads, with the common peroneal nerve running between them (20%). The group with anatomical variations of the sciatic nerve course displayed greater diversity of morphometric measurement results. There was a statistically significant correlation between the lower limb length and the distance from the sciatic nerve to the greater trochanter in the male specimens. On the other hand, in the female specimens, a statistically significant correlation was observed between the lower limb length and the distance from the sciatic nerve to the ischial tuberosity. The shortest distance from the sciatic nerve to the greater trochanter measured at the level of the inferior edge of the piriformis was 21 mm, while the shortest distance to the ischial tuberosity was 63 mm. Such correlations should be taken into account during invasive medical procedures performed in the gluteal region. Conclusions It is possible to distinguish several anatomical variations of the sciatic nerve course within the deep gluteal region. The statistically significant correlations between some anthropometric measurements were only present within particular groups of male and female limbs. PMID:26629744

Frequency of palmaris longus absence and its association with other anatomical variations in the Egyptian population.

PubMed

Raouf, Hoda Abdel; Kader, Ghada Abdel; Jaradat, Ahmed; Dharap, Amol; Fadel, Raouf; Salem, Abdel Halim

2013-07-01

The palmaris longus (PL) is one of the most variable muscles in the human body. Racial differences in its variation have been documented. Several studies have attempted to correlate PL absence with other anatomical variations. This study was conducted to determine the prevalence of absence of PL, correlate it with gender and body side and to determine its association with other anatomical variations in the Egyptian population. The presence of PL was clinically determined in 386 Egyptians using the standard technique. All subjects were examined for the presence of the flexor digitorum superficialis (FDS) to the fifth finger. Allen's test was done to assess the completeness of the superficial palmar arch (SPA). The overall prevalence of absence of the PL in Egyptian subjects was 50.8%. There was no significant difference in PL absence with regard to the body side but a significant difference was seen as regards gender and when bilateral absence of PL was compared to its unilateral absence. Absence of FDS tendon to the fifth finger was seen in 1.3% subjects. There was no association between the absence of the FDS tendon to the fifth finger and either presence or absence of PL and also between the absence of PL and the incompleteness of SPA in both genders. In conclusion, the prevalence of absence of PL in the Egyptian population represents one of the highest rates of absence to be reported for this muscle, which is significantly different from that in other ethnic groups. Copyright © 2013 Wiley Periodicals, Inc.

Ultrasound imaging of the thenar motor branch of the median nerve: a cadaveric study.

PubMed

Petrover, David; Bellity, Jonathan; Vigan, Marie; Nizard, Remy; Hakime, Antoine

2017-11-01

Anatomic variations of the median nerve (MN) increase the risk of iatrogenic injury during carpal tunnel release surgery. We investigated whether high-frequency ultrasonography could identify anatomic variations of the MN and its thenar motor branch (MBMN) in the carpal tunnel. For each volar wrist of healthy non-embalmed cadavers, the type of MN variant (Lanz classification), course and orientation of the MBMN, and presence of hypertrophic muscles were scored by 18-MHz ultrasound and then by dissection. MBMN was identified by ultrasound in all 30 wrists (15 subjects). By dissection, type 1, 2 and 3 variants were found in 84%, 3%, and 13% of wrists, respectively. Ultrasound had good agreement with dissection in identifying the variant type (kappa =0.9). With both techniques, extra-, sub-, and transligamentous courses were recorded in 65%, 31%, and 4% of cases, respectively. With both techniques, the bifid nerve, hypertrophic muscles, and bilateral symmetry for variant type were identified in 13.3%, 13.3%, and 86.7% of wrists, respectively. Agreement between ultrasound and dissection was excellent for the MBMN course and orientation (kappa =1). Ultrasound can be used reliably to identify anatomic variations of the MN and MBMN. It could be a useful tool before carpal tunnel release surgery. • Ultrasound can identify variations of the motor branch of the median nerve. • Ultrasound mapping should be used prior to carpal tunnel release surgery. • All sub-, extra-, and transligamentous courses were accurately identified. • Type 3 variants (bifid nerve), hypertrophic muscles, and bilateral symmetry were accurately identified.

ANATOMIC STUDY OF THE NERVOUS COMMUNICATION BETWEEN THE MEDIAN AND MUSCULOUCUTANEOUS NERVE.

PubMed

Caetano, Edie Benedito; Vieira, Luiz Ângelo; Cavalheiro, Cristina Schmitt; Razuk, Mauro; Almargo, Marco Antonio Pires; Caetano, Mauricio Ferreira

2016-01-01

The aim of this study was to analyze the incidence of nerve communication between the musculocutaneous and median nerve . Anatomical dissection of 40 limbs from 20 fetal cadavers was performed at the Laboratory of Anatomy, Faculdade de Ciências Médicas e da Saúde da Pontifícia Universidade Católica de São Paulo . A communicating branch was found in 10 upper limbs. In nine limbs there was a musculocutaneous-median anastomosis (type I); and in one limb there was a median-musculocutaneous anastomosis (type II) . It is very important to know these anatomical variations, especially when considering clinical examination, diagnostic, prognostic and surgical treatment. Level of Evidence IV, Case Series.

A case of double inferior vena cava with renal, ovarian and iliac vein variation.

PubMed

Ito, Taro; Ikeda, Yayoi

2018-01-01

We encountered a rare case of an anatomic variant of inferior vena cava (IVC) duplication with renal, ovarian and iliac vein variation in an 81-year-old Japanese female cadaver during a student dissection course of anatomy at Aichi Gakuin University School of Dentistry. The two IVCs ran upwards bilaterally to the abdominal aorta. The left IVC joined with the left renal vein (RV) to form a common trunk that crossed anterior to the aorta and ended at the right IVC. We detected a vein [interiliac vein (IiV)] connecting the two IVCs at the level of the aortic bifurcation. The IiV was formed by the union of two tributaries from the left IVC and a tributary from the left internal iliac vein (IIV) and ran obliquely upwards from left to right. Two right ovarian veins, arising separately from the ipsilateral pampiniform plexus, ran vertically in parallel to each other, and each one independently terminated at the right IVC and the right RV. Two right IIVs, connecting each other with small branches, ascended and separately joined the right external iliac vein. The right and left IIVs were connected to each other. These variations cause abnormal drainage, which could lead to clinical symptoms associated with the dysfunction of the vascular and urogenital systems. Here we describe the detailed anatomical features of the area and discuss the related anatomical and developmental aspects.

Anatomical variation of mesophyll conductance under potassium deficiency has a vital role in determining leaf photosynthesis.

PubMed

Lu, Zhifeng; Lu, Jianwei; Pan, Yonghui; Lu, Piaopiao; Li, Xiaokun; Cong, Rihuan; Ren, Tao

2016-11-01

Leaves exposed to potassium (K) deficiency usually present decreased mesophyll conductance (g m ) and photosynthesis (A). The relative contributions of leaf anatomical traits in determining g m have been quantified; however, anatomical variabilities related to low g m under K starvation remain imperfectly known. A one-dimensional model was used to quantify anatomical controls of the entire CO 2 diffusion pathway resistance within a leaf on two Brassica napus L. cultivars in response to K deficiency. Leaf photosynthesis of both cultivars was significantly decreased under K deficiency in parallel with down-regulated g m . The mesophyll conductance limitation contributed to more than one-half of A decline. The decreased internal air space in K-starved leaves was associated with the increase of gas-phase resistance. Potassium deficiency reduced liquid-phase conductance by decreasing the exposed surface area of chloroplasts per unit leaf area (S c /S), and enlarging the resistance of the cytoplasm that can be interpreted by the increasing distance of chloroplast from cell wall, and between adjacent chloroplasts. Additionally, the discrepancies of A between two cultivars were in part because of g m variations, ascribing to an altered S c /S. These results emphasize the important role of K on the regulation of g m by enhancing S c /S and reducing cytoplasm resistance. © 2016 John Wiley & Sons Ltd.

Evaluation of clinical use of OneDose™ metal oxide semiconductor field-effect transistor detectors compared to thermoluminescent dosimeters to measure skin dose for adult patients with acute lymphoblastic leukemia

PubMed Central

Al-Mohammed, Huda Ibrahim

2011-01-01

Background: Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to their bone marrow transplant. It involves the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore, it is important to measure and monitor the skin dose during the treatment. Thermoluminescent dosimeters (TLDs) and the OneDose™ metal oxide semiconductor field effect transistor (MOSFET) detectors are used during treatment delivery to measure the radiation dose and compare it with the target prescribed dose. Aims: The primary goal of this study was to measure the variation of skin dose using OneDose MOSFET detectors and TLD detectors, and compare the results with the target prescribed dose. The secondary aim was to evaluate the simplicity of use and determine if one system was superior to the other in clinical use. Material and Methods: The measurements involved twelve adult patients diagnosed with acute lymphoblastic leukemia. TLD and OneDose MOSFET dosimetry were performed at ten different anatomical sites of each patient. Results: The results showed that there was a variation between skin dose measured with OneDose MOSFET detectors and TLD in all patients. However, the variation was not significant. Furthermore, the results showed for every anatomical site there was no significant different between the prescribed dose and the dose measured by either TLD or OneDose MOSFET detectors. Conclusion: There were no significant differences between the OneDose MOSFET and TLDs in comparison to the target prescribed dose. However, OneDose MOSFET detectors give a direct read-out immediately after the treatment, and their simplicity of use to compare with TLD detectors may make them preferred for clinical use. PMID:22171243

Lip sun protection factor of a lipstick sunscreen.

PubMed

Gabard, B; Ademola, J

2001-01-01

There is a well-documented need for effective human UVA and UVB photoprotection. Since there are important anatomical variations, the sun protection factor (SPF) of a lipstick sunscreen was measured on the anatomical site intended for use. The SPF tests were performed according to Federal US and European COLIPA guidelines. Prior to performing a test on the lip, the minimal erythemal dose (MED) of the unprotected back skin was determined. Subsequently, the sunscreen SPF was measured on the anatomical target site (lip). The evaluator was blinded with respect to scoring the SPF of each sunscreen treatment. Individual test sites were assigned to one of the following treatment conditions: (1) no treatment (MED of unprotected skin); (2) test formulation; (3) reference standard. The MED on unprotected back skin was found to be 25% lower than on unprotected lip skin. The SPF of the lipstick sunscreen was measured 2 units lower than the SPF determined in the classical way on the back skin. It was hypothesized that the higher MED of the lower lip compared with back skin was due to the adaptation of this tissue to the continuous exposure to UV radiation. Copyright 2001 S. Karger AG, Basel

[Association of three anatomical variants of the anterior cerebral circulation].

PubMed

Reyes-Soto, Gervith; Pérez-Cruz, Julio; Delgado-Reyes, Luis; Ortega-Gutiérrez, César; Téllez-Palacios, Daniela

2012-01-01

As part of a study of the microsurgical anatomy of the pericallosal artery, we describe one brain with three unusual anatomical variants. From the autopsy of a 45 year-old female, we extracted the brain and all the arterial blood vessels were washed off with saline solution to be injected afterwards with red latex. The brain was then immersed in 10% formalin for two months. Finally, we dissected and measured the internal carotid artery segments, using a digital Vernier caliper under a Carl Zeiss OPMI surgical microscope with magnification of 6x up to 40x. The brain's weight was 1250 grams and three rare anatomical variants were found: 1) right accessory middle cerebral artery (ACMA-d), 2) right bihemispheric anterior cerebral artery (ACABihem-d), 3) median artery of the corpus callosum (AMCC). The association of the anatomical variations described previously is inconstant; furthermore, their appearance in a single case is rare.

Evidence for a genetic discontinuity between Neandertals and 24,000-year-old anatomically modern Europeans.

PubMed

Caramelli, David; Lalueza-Fox, Carles; Vernesi, Cristiano; Lari, Martina; Casoli, Antonella; Mallegni, Francesco; Chiarelli, Brunetto; Dupanloup, Isabelle; Bertranpetit, Jaume; Barbujani, Guido; Bertorelle, Giorgio

2003-05-27

During the late Pleistocene, early anatomically modern humans coexisted in Europe with the anatomically archaic Neandertals for some thousand years. Under the recent variants of the multiregional model of human evolution, modern and archaic forms were different but related populations within a single evolving species, and both have contributed to the gene pool of current humans. Conversely, the Out-of-Africa model considers the transition between Neandertals and anatomically modern humans as the result of a demographic replacement, and hence it predicts a genetic discontinuity between them. Following the most stringent current standards for validation of ancient DNA sequences, we typed the mtDNA hypervariable region I of two anatomically modern Homo sapiens sapiens individuals of the Cro-Magnon type dated at about 23 and 25 thousand years ago. Here we show that the mtDNAs of these individuals fall well within the range of variation of today's humans, but differ sharply from the available sequences of the chronologically closer Neandertals. This discontinuity is difficult to reconcile with the hypothesis that both Neandertals and early anatomically modern humans contributed to the current European gene pool.

Automatic categorization of anatomical landmark-local appearances based on diffeomorphic demons and spectral clustering for constructing detector ensembles.

PubMed

Hanaoka, Shouhei; Masutani, Yoshitaka; Nemoto, Mitsutaka; Nomura, Yukihiro; Yoshikawa, Takeharu; Hayashi, Naoto; Ohtomo, Kuni

2012-01-01

A method for categorizing landmark-local appearances extracted from computed tomography (CT) datasets is presented. Anatomical landmarks in the human body inevitably have inter-individual variations that cause difficulty in automatic landmark detection processes. The goal of this study is to categorize subjects (i.e., training datasets) according to local shape variations of such a landmark so that each subgroup has less shape variation and thus the machine learning of each landmark detector is much easier. The similarity between each subject pair is measured based on the non-rigid registration result between them. These similarities are used by the spectral clustering process. After the clustering, all training datasets in each cluster, as well as synthesized intermediate images calculated from all subject-pairs in the cluster, are used to train the corresponding subgroup detector. All of these trained detectors compose a detector ensemble to detect the target landmark. Evaluation with clinical CT datasets showed great improvement in the detection performance.

Some anatomical and physiological aspects of anal sexual practices.

PubMed

Agnew, J

1985-01-01

Anal manipulation and penetration produce stimulation enjoyed as sexual by some people. Although this type of sexual activity is not new, the current social climate of sexual freedom and experimentation has brought it out into the open. This paper reviews some of the anatomical, physiological, and behavioral aspects of this variation of human sexual gratification, and provides the practicing professional, who has to deal with questions on anal sexuality, with information on the subject and suitable background material and literature references for further study.

Endodontic and Clinical Considerations in the Management of Variable Anatomy in Mandibular Premolars: A Literature Review

PubMed Central

Hammo, Mohammad

2014-01-01

Mandibular premolars are known to have numerous anatomic variations of their roots and root canals, which are a challenge to treat endodontically. The paper reviews literature to detail the various clinically relevant anatomic considerations with detailed techniques and methods to successfully manage these anomalies. An emphasis and detailed description of every step of treatment including preoperative diagnosis, intraoperative identification and management, and surgical endodontic considerations for the successful management of these complex cases have been included. PMID:24895584

Increased revision rate with posterior tibial tunnel placement after using the 70-degree tibial guide in ACL reconstruction.

PubMed

Inderhaug, Eivind; Raknes, Sveinung; Østvold, Thomas; Solheim, Eirik; Strand, Torbjørn

2017-01-01

To map knee morphology radiographically in a population with a torn ACL and to investigate whether anatomic factors could be related to outcomes after ACL reconstruction at mid- to long-term follow-up. Further, we wanted to assess tibial tunnel placement after using the 70-degree "anti-impingement" tibial tunnel guide and investigate any relation between tunnel placement and revision surgery. Patients undergoing ACL reconstruction involving the 70-degree tibial guide from 2003 to 2008 were included. Two independent investigators analysed pre- and post-operative radiographs. Demographic data and information on revision surgery were collected from an internal database. Anatomic factors and post-operative tibial tunnel placements were investigated as predictors of revision. Three-hundred and seventy-seven patients were included in the study. A large anatomic variation with significant differences between men and women was seen. None of the anatomic factors could be related to a significant increase in revision rate. Patients with a posterior tibial tunnel placement, defined as 50 % or more posterior on the Amis and Jakob line, did, however, have a higher risk of revision surgery compared to patients with an anterior tunnel placement (P = 0.03). Use of the 70-degree tibial guide did result in a high incidence (47 %) of posterior tibial tunnel placements associated with an increased rate of revision surgery. The current study was, however, not able to identify any anatomic variation that could be related to a higher risk of revision surgery. Avoiding graft impingement from the femoral roof in anterior tibial tunnel placements is important, but the insight that overly posterior tunnel placement can lead to inferior outcome should also be kept in mind when performing ACL surgery. IV.

Experimental study of hemodynamics in the Circle of Willis.

PubMed

Zhu, Guangyu; Yuan, Qi; Yang, Jian; Yeo, Joon

2015-01-01

The Circle of Willis (CoW) is an important collateral pathway of the cerebral blood flow. An experimental study of the cerebral blood flow (CBF) distribution in different anatomical variations may help to a better understanding of the collateral mechanism of the CoW. An in-vitro test rig was developed to simulate the physiological cerebral blood flow in the CoW. Ten anatomical variations were considered in this study, include a set of different degrees of stenosis in L-ICA and L-ICA occlusion coexist with common anatomical variations. Volume flow rates of efferent arteries and pressure signals at the end of communicating arteries of each case were recorded. Physiological pressure waveforms were applied as inlet boundary condition. In the development of L-ICA stenosis, the total CBF decreases with the increase of stenosis degree. The blood supply of ipsilateral middle cerebral artery (MCA) was affected most by the stenosis of L-ICA. Anterior communicating artery (ACoA) and ipsilateral posterior communicating artery (PCoA) function as important collateral pathways of cerebral collateral circulation when unilateral stenosis occurred. The blood supply of anterior cerebral circulation was compensated by the posterior cerebral circulation through ipsilateral PCoA when L-ICA stenosis degree is greater than 40% and the affected side was compensated immediately by the unaffected side through ACoA. Blood flow of the anterior circulation and the total CBF reached the minimum among all cases studied when L-ICA occlusion coexist with the absence of PCoA. The results demonstrated the flow distribution patterns of the CoW under anatomical variations and clarified the collateral mechanism of the CoW. The flow ACoA is the most sensitive indexes to the morphology change of ipsilateral ICA. The relative independence of the circulation in anterior and posterior sections of the CoW is not broken and the function of ipsilateral PCoA is not activated until a severe stenosis of unilateral ICA occurs. PCoA is the most important collateral pathway of the collateral circulation and the missing of PCoA has the highest risk of stroke when the ipsilateral ICA has severe stenosis. These findings may provide the basis for future therapeutic and diagnosis applications.

The effect of dental artifacts, contrast media, and experience on interobserver contouring variations in head and neck anatomy.

PubMed

O'Daniel, Jennifer C; Rosenthal, David I; Garden, Adam S; Barker, Jerry L; Ahamad, Anesa; Ang, K Kian; Asper, Joshua A; Blanco, Angel I; de Crevoisier, Renaud; Holsinger, F Christopher; Patel, Chirag B; Schwartz, David L; Wang, He; Dong, Lei

2007-04-01

To investigate interobserver variability in the delineation of head-and-neck (H&N) anatomic structures on CT images, including the effects of image artifacts and observer experience. Nine observers (7 radiation oncologists, 1 surgeon, and 1 physician assistant) with varying levels of H&N delineation experience independently contoured H&N gross tumor volumes and critical structures on radiation therapy treatment planning CT images alongside reference diagnostic CT images for 4 patients with oropharynx cancer. Image artifacts from dental fillings partially obstructed 3 images. Differences in the structure volumes, center-of-volume positions, and boundary positions (1 SD) were measured. In-house software created three-dimensional overlap distributions, including all observers. The effects of dental artifacts and observer experience on contouring precision were investigated, and the need for contrast media was assessed. In the absence of artifacts, all 9 participants achieved reasonable precision (1 SD < or =3 mm all boundaries). The structures obscured by dental image artifacts had larger variations when measured by the 3 metrics (1 SD = 8 mm cranial/caudal boundary). Experience improved the interobserver consistency of contouring for structures obscured by artifacts (1 SD = 2 mm cranial/caudal boundary). Interobserver contouring variability for anatomic H&N structures, specifically oropharyngeal gross tumor volumes and parotid glands, was acceptable in the absence of artifacts. Dental artifacts increased the contouring variability, but experienced participants achieved reasonable precision even with artifacts present. With a staging contrast CT image as a reference, delineation on a noncontrast treatment planning CT image can achieve acceptable precision.

ANATOMIC STUDY OF THE NERVOUS COMMUNICATION BETWEEN THE MEDIAN AND MUSCULOUCUTANEOUS NERVE

PubMed Central

Caetano, Edie Benedito; Vieira, Luiz Ângelo; Cavalheiro, Cristina Schmitt; Razuk, Mauro; Almargo, Marco Antonio Pires; Caetano, Mauricio Ferreira

2016-01-01

ABSTRACT Objective: The aim of this study was to analyze the incidence of nerve communication between the musculocutaneous and median nerve. Methods: Anatomical dissection of 40 limbs from 20 fetal cadavers was performed at the Laboratory of Anatomy, Faculdade de Ciências Médicas e da Saúde da Pontifícia Universidade Católica de São Paulo. Results: A communicating branch was found in 10 upper limbs. In nine limbs there was a musculocutaneous-median anastomosis (type I); and in one limb there was a median-musculocutaneous anastomosis (type II). Conclusion: It is very important to know these anatomical variations, especially when considering clinical examination, diagnostic, prognostic and surgical treatment. Level of Evidence IV, Case Series. PMID:28243174

Segmentation of medical images using explicit anatomical knowledge

NASA Astrophysics Data System (ADS)

Wilson, Laurie S.; Brown, Stephen; Brown, Matthew S.; Young, Jeanne; Li, Rongxin; Luo, Suhuai; Brandt, Lee

1999-07-01

Knowledge-based image segmentation is defined in terms of the separation of image analysis procedures and representation of knowledge. Such architecture is particularly suitable for medical image segmentation, because of the large amount of structured domain knowledge. A general methodology for the application of knowledge-based methods to medical image segmentation is described. This includes frames for knowledge representation, fuzzy logic for anatomical variations, and a strategy for determining the order of segmentation from the modal specification. This method has been applied to three separate problems, 3D thoracic CT, chest X-rays and CT angiography. The application of the same methodology to such a range of applications suggests a major role in medical imaging for segmentation methods incorporating representation of anatomical knowledge.

Sources of variation in hair cortisol in wild and captive non-human primates.

PubMed

Fourie, Nicolaas H; Brown, Janine L; Jolly, Clifford J; Phillips-Conroy, Jane E; Rogers, Jeffrey; Bernstein, Robin M

2016-04-01

Hair cortisol analysis is a potentially powerful tool for evaluating adrenal function and chronic stress. However, the technique has only recently been applied widely to studies of wildlife, including primates, and there are numerous practical and technical factors that should be considered to ensure good quality data and the validity of results and conclusions. Here we report on various intrinsic and extrinsic sources of variation in hair cortisol measurements in wild and captive primates. Hair samples from both wild and captive primates revealed that age and sex can affect hair cortisol concentrations; these effects need to be controlled for when making comparisons between individual animals or populations. Hair growth rates also showed considerable inter-specific variation among a number of primate species. We describe technical limitations of hair analyses and variation in cortisol concentrations as a function of asynchronous hair growth, anatomical site of collection, and the amount and numbers of hair/s used for cortisol extraction. We discuss these sources of variation and their implications for proper study design and interpretation of results. Published by Elsevier GmbH.

Investigations of potential endocrine disruption and sexual dimorphism in nestling tree swallows (Tachycineta bicolor) with a range of PCB body burdens

USGS Publications Warehouse

Yorks, A.L.; Rattner, B.A.; Melancon, M.J.; Bakst, M.R.

1998-01-01

Polychlorinated biphenyls (PCBs) elicit endocrine disruptive effects in many species, including birds. Tree swallows (Tachycineta bicolor) were studied at eight sites, located in Maryland, Pennsylvania, and New York, with a range of PCB contamination to determine effects on gender and gonadal development of nestling offipring. Blood samples were collected from nestlings and genetic sex was determined by polymerase chain reaction amplification of sex chromatin in nucleated red blood cells. Gonads were excised and fixed for subsequent gross and histologic examination. PCB analyses of twelve-day old nestlings indicated that residue concentrations varied considerably among the eight sites. Of the 145 nestlings examined anatomically, the phenotypic sex ratio was 53% female and 47% male. No intersexes were observed. Histological observations revealed some variation such as numbers of spermatogonia and stages of follicular development among individuals. Genotypic evaluation of the 145 nestlings revealed complete concordance with phenotypic observations. Although there were significant differences in PCB exposure among study sites, there was no evidence of abnormal gonadal development or anatomical gender alteration in nestling Tree swallows.

Anomalous Posterior Intercostal Arterial Trunk Arising From the Abdominal Aorta

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jie, Bing, E-mail: jbshh@163.com; Yu, Dong, E-mail: yudong-mail@126.com; Jiang, Sen, E-mail: jasfly77@vip.163.com

A common trunk of the ipsilateral posterior intercostal artery (PIA) arising from the thoracic aorta is usually an anatomical variation. However, a common trunk of bilateral posterior intercostal arterial trunk (PIAT) arising from the abdominal aorta is rare. It is important to recognize this anatomical variation of PIA when performing interventional radiological procedures. We present a rare case of an anomalous PIAT that originated from the abdominal aorta in a patient with hemoptysis caused by tuberculosis sequelae. Bilateral 4th to 11th PIAs arose from a common trunk and the trunk arising from the posterior aspect of the abdominal aorta atmore » the level of T12/L1 intervertebral space. The pathological right 4th and 5th PIAs and bronchial arteries were embolized. Hemoptysis has been controlled for 3 months.« less

An Analysis of the Anatomic Variations of the Paranasal Sinuses and Ethmoid Roof Using Computed Tomography

PubMed Central

Kaplanoglu, Hatice; Kaplanoglu, Veysel; Dilli, Alper; Toprak, Ugur; Hekimoğlu, Baki

2013-01-01

Objective: To determine the Keros classification and asymmetrical distribution rates of the ethmoid roof and the frequency of anatomic variations of the paranasal sinuses. Materials and Methods: Paranasal sinus scans of 500 patients obtained using computed tomography were evaluated retrospectively. Measurements were performed using a coronal plan with right-left comparison and with distance measurement techniques. The depth of the lateral lamella was calculated by subtracting the depth of the cribriform plate from the depth of the medial ethmoid roof. The results were classified according to their Keros classification. Any asymmetries in the ethmoid roof depth and fovea ethmoidalis configuration were examined. The anatomic variations frequently encountered in paranasal sinuses (pneumatized middle concha, paradoxical middle concha, agger nasi cells, Haller cells, Onodi cells, etc.) were defined. Results: The mean height of the lateral lamella cribriform plate (LLCP) was 4.92±1.70 mm. The cases were classified as 13.4% Keros Type I, 76.1% Keros Type II, and 10.5% Keros Type III. There was asymmetry in the LLCP depths of 80% of the cases, and a configuration asymmetry in the fovea in 35% of the cases. In 32% of the cases with fovea configuration asymmetry, there was also asymmetry in the height of the right and left LLCP. The most frequent variations were nasal septum deviation (81.8%), agger nasi cells (63.8%), intralamellar air cells (45%), and concha bullosa (30%). Conclusion: Using the Keros classification for LLCP height, higher rates of Keros Type I were found in other studies than in our study. The most frequent classification was Keros Type II. The paranasal sinus variations in each patient should be carefully evaluated. The data obtained from these evaluations can prevent probable complications by informing rhinologists performing endoscopic sinus surgery about preoperative and intraoperative processes. PMID:25610263

Magnetic resonance cholangiographic evaluation of intrahepatic and extrahepatic bile duct variations

PubMed Central

Sureka, Binit; Bansal, Kalpana; Patidar, Yashwant; Arora, Ankur

2016-01-01

Biliary anatomy and its common and uncommon variations are of considerable clinical significance when performing living donor transplantation, radiological interventions in hepatobiliary system, laparoscopic cholecystectomy, and liver resection (hepatectomy, segmentectomy). Because of increasing trend found in the number of liver transplant surgeries being performed, magnetic resonance cholangiopancreatography (MRCP) has become the modality of choice for noninvasive evaluation of abnormalities of the biliary tract. The purpose of this study is to describe the anatomic variations of the intrahepatic and extrahepatic biliary tree. PMID:27081220

Anatomy of the sural nerve: cadaver study and literature review.

PubMed

Riedl, Otto; Frey, Manfred

2013-04-01

The sural nerve is commonly used as donor for nerve grafting. Contrary to its constant retromalleolar position, formation and course of the proximal sural nerve show great variability. The coexistence of different and deceptive terminologies contributes to the complexity, and reviewing the international literature is confusing. Because detailed anatomical knowledge is essential for efficient and safe sural nerve harvesting, this study aims to bring clarity. Previous sural nerve reports listed in the PubMed database and established anatomical textbooks were reviewed. Different terminologies were compared and adjusted. Anatomical details and variations were noted. Subtle prospective anatomical dissections and comparison with actual data followed. Two hundred twenty-one relevant reports were identified and worked up going back to the nineteenth century. Fourteen established German and English language anatomical textbooks were reviewed. Thirty lower limbs were dissected. In total, this study pools the information of more than 2500 sural nerves. This study covers all information about the sural nerve anatomy published internationally. The coexistence of different and confusing terminologies is pinpointed and adjusted to allow comparison of previous reports and to gain a coordinated data pool of more than 2500 investigated sural nerves. Detailed features are clearly described and summarized, findings from the authors' own prospective dissections complete these data, and the prior existing anatomical confusion is resolved. Finally, clinical implications are described.

Quantitative assessment of anatomical change using a virtual proton depth radiograph for adaptive head and neck proton therapy.

PubMed

Wang, Peng; Yin, Lingshu; Zhang, Yawei; Kirk, Maura; Song, Gang; Ahn, Peter H; Lin, Alexander; Gee, James; Dolney, Derek; Solberg, Timothy D; Maughan, Richard; McDonough, James; Teo, Boon-Keng Kevin

2016-03-08

The aim of this work is to demonstrate the feasibility of using water-equivalent thickness (WET) and virtual proton depth radiographs (PDRs) of intensity corrected cone-beam computed tomography (CBCT) to detect anatomical change and patient setup error to trigger adaptive head and neck proton therapy. The planning CT (pCT) and linear accelerator (linac) equipped CBCTs acquired weekly during treatment of a head and neck patient were used in this study. Deformable image registration (DIR) was used to register each CBCT with the pCT and map Hounsfield units (HUs) from the planning CT (pCT) onto the daily CBCT. The deformed pCT is referred as the corrected CBCT (cCBCT). Two dimensional virtual lateral PDRs were generated using a ray-tracing technique to project the cumulative WET from a virtual source through the cCBCT and the pCT onto a virtual plane. The PDRs were used to identify anatomic regions with large variations in the proton range between the cCBCT and pCT using a threshold of 3 mm relative difference of WET and 3 mm search radius criteria. The relationship between PDR differences and dose distribution is established. Due to weight change and tumor response during treatment, large variations in WETs were observed in the relative PDRs which corresponded spatially with an increase in the number of failing points within the GTV, especially in the pharynx area. Failing points were also evident near the posterior neck due to setup variations. Differences in PDRs correlated spatially to differences in the distal dose distribution in the beam's eye view. Virtual PDRs generated from volumetric data, such as pCTs or CBCTs, are potentially a useful quantitative tool in proton therapy. PDRs and WET analysis may be used to detect anatomical change from baseline during treatment and trigger further analysis in adaptive proton therapy.

AnatomicalTerms.info: heading for an online solution to the anatomical synonym problem hurdles in data-reuse from the Terminologia Anatomica and the foundational model of anatomy and potentials for future development.

PubMed

Gobée, O Paul; Jansma, Daniël; DeRuiter, Marco C

2011-10-01

The many synonyms for anatomical structures confuse medical students and complicate medical communication. Easily accessible translations would alleviate this problem. None of the presently available resources-Terminologia Anatomica (TA), digital terminologies such as the Foundational Model of Anatomy (FMA), and websites-are fully satisfactory to this aim. Internet technologies offer new possibilities to solve the problem. Several authors have called for an online TA. An online translation resource should be easily accessible, user-friendly, comprehensive, expandable, and its quality determinable. As first step towards this goal, we built a translation website that we named www.AnatomicalTerms.info, based on the database of the FMA. It translates between English, Latin, eponyms, and to a lesser extent other languages, and presently contains over 31,000 terms for 7,250 structures, covering 95% of TA. In addition, it automatically presents searches for images, documents and anatomical variations regarding the sought structure. Several terminological and conceptual issues were encountered in transferring data from TA and FMA into AnatomicalTerms.info, resultant from these resources' different set-ups (paper versus digital) and targets (machine versus human-user). To the best of our knowledge, AnatomicalTerms.info is unique in its combination of user-friendliness and comprehensiveness. As next step, wiki-like expandability will be added to enable open contribution of clinical synonyms and terms in different languages. Specific quality measures will be taken to strike a balance between open contribution and quality assurance. AnatomicalTerms.info's mechanism that "translates" terms to structures furthermore may enhance targeted searching by linking images, descriptions, and other anatomical resources to the structures. Copyright © 2011 Wiley-Liss, Inc.

The missed inferior alveolar block: a new look at an old problem.

PubMed

Milles, M

1984-01-01

A variation of a previously described technique to obtain mandibular block anesthesia is presented. This technique varies from those previously described in that is uses palpable anatomic landmarks, both extra- and intraoral, to orient the placement of the needle. This technique relies on several readily observed landmarks and the integration of these landmarks. Because palpable landmarks are used, consistent results can be easily obtained even in patients who present with a wide variety of anatomical variances which otherwise make this injection technique difficult and prone to failure.

Thoracoscopic splanchnicectomy as a palliative procedure for pain relief in carcinoma pancreas.

PubMed

Prasad, Arun; Choudhry, Piush; Kaul, Sunil; Srivastava, Gaurav; Ali, Mudasir

2009-04-01

Thoracoscopic splanchnicectomy has been used for the management of upper abdominal pain syndromes as an alternative to celiac plexus block for conditions such as chronic pancreatitis or supramesocolic malignant neoplasms, including unresectable pancreatic cancer. This procedure is similar to the percutaneous block with a higher degree of precision and avoids the side effects associated with the local diffusion of neurolytic solutions. Thoracoscopic splanchnicectomy appears to be a better treatment in such cases as the procedure is done under direct vision and less dependent on anatomical variations.

Thoracoscopic splanchnicectomy as a palliative procedure for pain relief in carcinoma pancreas

PubMed Central

Prasad, Arun; Choudhry, Piush; Kaul, Sunil; Srivastava, Gaurav; Ali, Mudasir

2009-01-01

Thoracoscopic splanchnicectomy has been used for the management of upper abdominal pain syndromes as an alternative to celiac plexus block for conditions such as chronic pancreatitis or supramesocolic malignant neoplasms, including unresectable pancreatic cancer. This procedure is similar to the percutaneous block with a higher degree of precision and avoids the side effects associated with the local diffusion of neurolytic solutions. Thoracoscopic splanchnicectomy appears to be a better treatment in such cases as the procedure is done under direct vision and less dependent on anatomical variations. PMID:19727377

A feature-based developmental model of the infant brain in structural MRI.

PubMed

Toews, Matthew; Wells, William M; Zöllei, Lilla

2012-01-01

In this paper, anatomical development is modeled as a collection of distinctive image patterns localized in space and time. A Bayesian posterior probability is defined over a random variable of subject age, conditioned on data in the form of scale-invariant image features. The model is automatically learned from a large set of images exhibiting significant variation, used to discover anatomical structure related to age and development, and fit to new images to predict age. The model is applied to a set of 230 infant structural MRIs of 92 subjects acquired at multiple sites over an age range of 8-590 days. Experiments demonstrate that the model can be used to identify age-related anatomical structure, and to predict the age of new subjects with an average error of 72 days.

Retromolar foramen and canal: a comprehensive review on its anatomy and clinical applications.

PubMed

Kumar Potu, B; Jagadeesan, S; Bhat, K M R; Rao Sirasanagandla, S

2013-06-01

The retromolar foramen (RMF) and retromolar canal (RMC) are the anatomical structures of the mandible located in retromolar fossa behind the third molar tooth. This foramen and canal contain neurovascular structures which provide accessory/additional innervation to the mandibular molars and the buccal area. These neurovascular contents of the canal gain more importance in medical and dental practice, because these elements are vulnerable to damage during placement of osteointegrated implants, endodontic treatment and sagittal split osteotomy surgeries and a detailed knowledge of this anatomical variation would be vital in understanding failed inferior alveolar nerve blockage, spread of infection and also metastasis. Although few studies have been conducted in the past showing the incidence and types in different population groups, a lacunae in comprehensive review of this structure is lacking. Though this variation posed challenging situations for the practicing surgeons, it has been quite neglected and the incidence of it is not well presented in all the textbooks. Hence, we made an attempt to provide a consolidated review regarding variations and clinical applications of the RMF and RMC. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Incomplete Hippocampal Inversion: A Comprehensive MRI Study of Over 2000 Subjects.

PubMed

Cury, Claire; Toro, Roberto; Cohen, Fanny; Fischer, Clara; Mhaya, Amel; Samper-González, Jorge; Hasboun, Dominique; Mangin, Jean-François; Banaschewski, Tobias; Bokde, Arun L W; Bromberg, Uli; Buechel, Christian; Cattrell, Anna; Conrod, Patricia; Flor, Herta; Gallinat, Juergen; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Ittermann, Bernd; Lemaitre, Hervé; Martinot, Jean-Luc; Nees, Frauke; Paillère Martinot, Marie-Laure; Orfanos, Dimitri P; Paus, Tomas; Poustka, Luise; Smolka, Michael N; Walter, Henrik; Whelan, Robert; Frouin, Vincent; Schumann, Gunter; Glaunès, Joan A; Colliot, Olivier

2015-01-01

The incomplete-hippocampal-inversion (IHI), also known as malrotation, is an atypical anatomical pattern of the hippocampus, which has been reported in healthy subjects in different studies. However, extensive characterization of IHI in a large sample has not yet been performed. Furthermore, it is unclear whether IHI are restricted to the medial-temporal lobe or are associated with more extensive anatomical changes. Here, we studied the characteristics of IHI in a community-based sample of 2008 subjects of the IMAGEN database and their association with extra-hippocampal anatomical variations. The presence of IHI was assessed on T1-weighted anatomical magnetic resonance imaging (MRI) using visual criteria. We assessed the association of IHI with other anatomical changes throughout the brain using automatic morphometry of cortical sulci. We found that IHI were much more frequent in the left hippocampus (left: 17%, right: 6%, χ(2)-test, p < 10(-28)). Compared to subjects without IHI, subjects with IHI displayed morphological changes in several sulci located mainly in the limbic lobe. Our results demonstrate that IHI are a common left-sided phenomenon in normal subjects and that they are associated with morphological changes outside the medial temporal lobe.

Incomplete Hippocampal Inversion: A Comprehensive MRI Study of Over 2000 Subjects

PubMed Central

Cury, Claire; Toro, Roberto; Cohen, Fanny; Fischer, Clara; Mhaya, Amel; Samper-González, Jorge; Hasboun, Dominique; Mangin, Jean-François; Banaschewski, Tobias; Bokde, Arun L. W.; Bromberg, Uli; Buechel, Christian; Cattrell, Anna; Conrod, Patricia; Flor, Herta; Gallinat, Juergen; Garavan, Hugh; Gowland, Penny; Heinz, Andreas; Ittermann, Bernd; Lemaitre, Hervé; Martinot, Jean-Luc; Nees, Frauke; Paillère Martinot, Marie-Laure; Orfanos, Dimitri P.; Paus, Tomas; Poustka, Luise; Smolka, Michael N.; Walter, Henrik; Whelan, Robert; Frouin, Vincent; Schumann, Gunter; Glaunès, Joan A.; Colliot, Olivier

2015-01-01

The incomplete-hippocampal-inversion (IHI), also known as malrotation, is an atypical anatomical pattern of the hippocampus, which has been reported in healthy subjects in different studies. However, extensive characterization of IHI in a large sample has not yet been performed. Furthermore, it is unclear whether IHI are restricted to the medial-temporal lobe or are associated with more extensive anatomical changes. Here, we studied the characteristics of IHI in a community-based sample of 2008 subjects of the IMAGEN database and their association with extra-hippocampal anatomical variations. The presence of IHI was assessed on T1-weighted anatomical magnetic resonance imaging (MRI) using visual criteria. We assessed the association of IHI with other anatomical changes throughout the brain using automatic morphometry of cortical sulci. We found that IHI were much more frequent in the left hippocampus (left: 17%, right: 6%, χ2−test, p < 10−28). Compared to subjects without IHI, subjects with IHI displayed morphological changes in several sulci located mainly in the limbic lobe. Our results demonstrate that IHI are a common left-sided phenomenon in normal subjects and that they are associated with morphological changes outside the medial temporal lobe. PMID:26733822

Optogenetic Activation of a Lateral Hypothalamic-Ventral Tegmental Drive-Reward Pathway.

PubMed

Gigante, Eduardo D; Benaliouad, Faiza; Zamora-Olivencia, Veronica; Wise, Roy A

2016-01-01

Electrical stimulation of the lateral hypothalamus can motivate feeding or can serve as a reward in its own right. It remains unclear whether the same or independent but anatomically overlapping circuitries mediate the two effects. Electrical stimulation findings implicate medial forebrain bundle (MFB) fibers of passage in both effects, and optogenetic studies confirm a contribution from fibers originating in the lateral hypothalamic area and projecting to or through the ventral tegmental area. Here we report that optogenetic activation of ventral tegmental fibers from cells of origin in more anterior or posterior portions of the MFB failed to induce either reward or feeding. The feeding and reward induced by optogenetic activation of fibers from the lateral hypothalamic cells of origin were influenced similarly by variations in stimulation pulse width and pulse frequency, consistent with the hypothesis of a common substrate for the two effects. There were, however, several cases where feeding but not self-stimulation or self-stimulation but not feeding were induced, consistent with the hypothesis that distinct but anatomically overlapping systems mediate the two effects. Thus while optogenetic stimulation provides a more selective tool for characterizing the mechanisms of stimulation-induced feeding and reward, it does not yet resolve the question of common or independent substrates.

Probabilistic modeling of anatomical variability using a low dimensional parameterization of diffeomorphisms.

PubMed

Zhang, Miaomiao; Wells, William M; Golland, Polina

2017-10-01

We present an efficient probabilistic model of anatomical variability in a linear space of initial velocities of diffeomorphic transformations and demonstrate its benefits in clinical studies of brain anatomy. To overcome the computational challenges of the high dimensional deformation-based descriptors, we develop a latent variable model for principal geodesic analysis (PGA) based on a low dimensional shape descriptor that effectively captures the intrinsic variability in a population. We define a novel shape prior that explicitly represents principal modes as a multivariate complex Gaussian distribution on the initial velocities in a bandlimited space. We demonstrate the performance of our model on a set of 3D brain MRI scans from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Our model yields a more compact representation of group variation at substantially lower computational cost than the state-of-the-art method such as tangent space PCA (TPCA) and probabilistic principal geodesic analysis (PPGA) that operate in the high dimensional image space. Copyright © 2017 Elsevier B.V. All rights reserved.

A National Trial on Differences in Cerebral Perfusion Pressure Values by Measurement Location.

PubMed

McNett, Molly M; Bader, Mary Kay; Livesay, Sarah; Yeager, Susan; Moran, Cristina; Barnes, Arianna; Harrison, Kimberly R; Olson, DaiWai M

2018-04-01

Cerebral perfusion pressure (CPP) is a key parameter in management of brain injury with suspected impaired cerebral autoregulation. CPP is calculated by subtracting intracranial pressure (ICP) from mean arterial pressure (MAP). Despite consensus on importance of CPP monitoring, substantial variations exist on anatomical reference points used to measure arterial MAP when calculating CPP. This study aimed to identify differences in CPP values based on measurement location when using phlebostatic axis (PA) or tragus (Tg) as anatomical reference points. The secondary study aim was to determine impact of differences on patient outcomes at discharge. This was a prospective, repeated measures, multi-site national trial. Adult ICU patients with neurological injury necessitating ICP and CPP monitoring were consecutively enrolled from seven sites. Daily MAP/ICP/CPP values were gathered with the arterial transducer at the PA, followed by the Tg as anatomical reference points. A total of 136 subjects were enrolled, resulting in 324 paired observations. There were significant differences for CPP when comparing values obtained at PA and Tg reference points (p < 0.000). Differences remained significant in repeated measures model when controlling for clinical factors (mean CPP-PA = 80.77, mean CPP-Tg = 70.61, p < 0.000). When categorizing CPP as binary endpoint, 18.8% of values were identified as adequate with PA values, yet inadequate with CPP values measured at the Tg. Findings identify numerical differences for CPP based on anatomical reference location and highlight importance of a standard reference point for both clinical practice and future trials to limit practice variations and heterogeneity of findings.

Defining the common femoral artery: Insights from the femoral arterial access with ultrasound trial.

PubMed

Seto, Arnold H; Tyler, Jeffrey; Suh, William M; Harrison, Alexander T; Vera, Jesus A; Zacharias, Soni J; Daly, Timothy S; Sparling, Jeffrey M; Patel, Pranav M; Kern, Morton J; Abu-Fadel, Mazen

2017-06-01

We sought to establish the typical location of the common femoral artery (CFA) bifurcation, the origin and most inferior reflection of the inferior epigastric artery (IEA) relative to the femoral head (FH) and whether patient demographics predicted anatomical variations. In the absence of ultrasound guidance or prior imaging, the precise location of the CFA bifurcation and IEA can only be determined following access site angiography. Fluoroscopic landmarks are commonly used to estimate the location of the CFA bifurcation, but the position of the IEA is less well characterized. Prospectively collected data on 989 patients with femoral angiography in the FAUST trial were analyzed. The level of CFA bifurcation and the origin and most inferior reflection of the IEA were classified by angiography. Logistic regression was used to explore whether baseline demographics were associated with anatomic variations. The CFA bifurcation occurs below the middle 1/3 rd of the femoral head in 95% of patients, and no patient factors are predictive of a high bifurcation. The IEA origin has a more variable anatomically pattern, with high BSA, male gender, and white race associated with a low IEA origin. Operators should attempt to access the CFA at the level of the middle 1/3 rd of the FH to maximize the chance of CFA cannulation. However, this location carries an 11% risk of being at or above the IEA origin. Baseline demographics were of limited utility for predicting anatomic variants of the CFA bifurcation and the course of the IEA. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Group-level variations in motor representation areas of thenar and anterior tibial muscles: Navigated Transcranial Magnetic Stimulation Study.

PubMed

Niskanen, Eini; Julkunen, Petro; Säisänen, Laura; Vanninen, Ritva; Karjalainen, Pasi; Könönen, Mervi

2010-08-01

Navigated transcranial magnetic stimulation (TMS) can be used to stimulate functional cortical areas at precise anatomical location to induce measurable responses. The stimulation has commonly been focused on anatomically predefined motor areas: TMS of that area elicits a measurable muscle response, the motor evoked potential. In clinical pathologies, however, the well-known homunculus somatotopy theory may not be straightforward, and the representation area of the muscle is not fixed. Traditionally, the anatomical locations of TMS stimulations have not been reported at the group level in standard space. This study describes a methodology for group-level analysis by investigating the normal representation areas of thenar and anterior tibial muscle in the primary motor cortex. The optimal representation area for these muscles was mapped in 59 healthy right-handed subjects using navigated TMS. The coordinates of the optimal stimulation sites were then normalized into standard space to determine the representation areas of these muscles at the group-level in healthy subjects. Furthermore, 95% confidence interval ellipsoids were fitted into the optimal stimulation site clusters to define the variation between subjects in optimal stimulation sites. The variation was found to be highest in the anteroposterior direction along the superior margin of the precentral gyrus. These results provide important normative information for clinical studies assessing changes in the functional cortical areas because of plasticity of the brain. Furthermore, it is proposed that the presented methodology to study TMS locations at the group level on standard space will be a suitable tool for research purposes in population studies. 2010 Wiley-Liss, Inc.

Sinus anatomy associated with inadvertent cerebrospinal fluid leak during functional endoscopic sinus surgery.

PubMed

Heaton, Chase M; Goldberg, Andrew N; Pletcher, Steven D; Glastonbury, Christine M

2012-07-01

Anatomic variations in skull base anatomy may predispose the surgeon to inadvertent skull base injury with resultant cerebrospinal fluid (CSF) leak during functional endoscopic sinus surgery (ESS). Our objective was to compare preoperative sinus imaging of patients who underwent FESS with and without CSF leak to elucidate these variations. In this retrospective case-control study, 18 patients with CSF leak following FESS for chronic rhinosinusitis (CRS) from 2000 to 2011 were compared to 18 randomly selected patients who underwent preoperative imaging for FESS for CRS. Measurements were obtained from preoperative computed tomography images with specific attention to anatomic differences in cribriform plate and ethmoid roof heights in the coronal plane, and the skull base angle in the sagittal plane. Mean values of measured variables were compared using a nonparametric Mann-Whitney test. When compared to controls, patients with CSF leak demonstrated a greater angle of the skull base in the sagittal plane (P < .001) and a greater slope of the skull base in the coronal plane (P < .006). A lower cribriform height relative to ethmoid roof height was also noted in cases of CSF leak as compared to controls (P < .04). A steep skull base angle in the sagittal plane, a greater slope of the skull base in the coronal plane, and a low cribriform height relative to the ethmoid roof predispose the patient to CSF leak during FESS. Preoperative review of imaging with specific attention paid to these anatomic variations may help to prevent iatrogenic CSF leak. Copyright © 2012 The American Laryngological, Rhinological, and Otological Society, Inc.

Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness

PubMed Central

Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

2015-01-01

The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010–2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate. PMID:26305893

Plastic Response of Tracheids in Pinus pinaster in a Water-Limited Environment: Adjusting Lumen Size instead of Wall Thickness.

PubMed

Carvalho, Ana; Nabais, Cristina; Vieira, Joana; Rossi, Sergio; Campelo, Filipe

2015-01-01

The formation of wood results from cambial activity and its anatomical properties reflect the variability of environmental conditions during the growing season. Recently, it was found that wood density variations in conifers growing under cold-limited environment result from the adjustment of cell wall thickness (CWT) to temperature. Additionally, it is known that intra-annual density fluctuations (IADFs) are formed in response to precipitation after the summer drought. Although IADFs are frequent in Mediterranean conifers no study has yet been conducted to determine if these structures result from the adjustment of lumen diameter (LD) or CWT to soil water availability. Our main objective is to investigate the intra-ring variation of wood anatomical features (LD and CWT) in Pinus pinaster Ait. growing under a water-limited environment. We compared the tracheidograms of LD and CWT for the years 2010-2013 in P. pinaster growing in the west coast of Portugal. Our results suggest a close association between LD and soil moisture content along the growing season, reinforcing the role of water availability in determining tracheid size. Compared with CWT, LD showed a higher intra- and inter-annual variability suggesting its strong adjustment value to variations in water availability. The formation of a latewood IADF appears to be predisposed by higher rates of cell production in spring and triggered by early autumn precipitation. Our findings reinforce the crucial role of water availability on cambial activity and wood formation in Mediterranean conifers, and emphasize the high plasticity of wood anatomical features under Mediterranean climate.

Routine exposure of recurrent laryngeal nerve in thyroid surgery can prevent nerve injury.

PubMed

Shen, Chenling; Xiang, Mingliang; Wu, Hao; Ma, Yan; Chen, Li; Cheng, Lan

2013-06-15

To determine the value of dissecting the recurrent laryngeal nerve during thyroid surgery with respect to preventing recurrent laryngeal nerve injury, we retrospectively analyzed clinical data from 5 344 patients undergoing thyroidectomy. Among these cases, 548 underwent dissection of the recurrent laryngeal nerve, while 4 796 did not. There were 12 cases of recurrent laryngeal nerve injury following recurrent laryngeal nerve dissection (injury rate of 2.2%) and 512 cases of recurrent laryngeal nerve injury in those not undergoing nerve dissection (injury rate of 10.7%). This difference remained statistically significant between the two groups in terms of type of thyroid disease, type of surgery, and number of surgeries. Among the 548 cases undergoing recurrent laryngeal nerve dissection, 128 developed anatomical variations of the recurrent laryngeal nerve (incidence rate of 23.4%), but no recurrent laryngeal nerve injury was found. In addition, the incidence of recurrent laryngeal nerve injury was significantly lower in patients with the inferior parathyroid gland and middle thyroid veins used as landmarks for locating the recurrent laryngeal nerve compared with those with the entry of the recurrent laryngeal nerve into the larynx as a landmark. These findings indicate that anatomical variations of the recurrent laryngeal nerve are common, and that dissecting the recurrent laryngeal nerve during thyroid surgery is an effective means of preventing nerve injury.

Routine exposure of recurrent laryngeal nerve in thyroid surgery can prevent nerve injury★

PubMed Central

Shen, Chenling; Xiang, Mingliang; Wu, Hao; Ma, Yan; Chen, Li; Cheng, Lan

2013-01-01

To determine the value of dissecting the recurrent laryngeal nerve during thyroid surgery with respect to preventing recurrent laryngeal nerve injury, we retrospectively analyzed clinical data from 5 344 patients undergoing thyroidectomy. Among these cases, 548 underwent dissection of the recurrent laryngeal nerve, while 4 796 did not. There were 12 cases of recurrent laryngeal nerve injury following recurrent laryngeal nerve dissection (injury rate of 2.2%) and 512 cases of recurrent laryngeal nerve injury in those not undergoing nerve dissection (injury rate of 10.7%). This difference remained statistically significant between the two groups in terms of type of thyroid disease, type of surgery, and number of surgeries. Among the 548 cases undergoing recurrent laryngeal nerve dissection, 128 developed anatomical variations of the recurrent laryngeal nerve (incidence rate of 23.4%), but no recurrent laryngeal nerve injury was found. In addition, the incidence of recurrent laryngeal nerve injury was significantly lower in patients with the inferior parathyroid gland and middle thyroid veins used as landmarks for locating the recurrent laryngeal nerve compared with those with the entry of the recurrent laryngeal nerve into the larynx as a landmark. These findings indicate that anatomical variations of the recurrent laryngeal nerve are common, and that dissecting the recurrent laryngeal nerve during thyroid surgery is an effective means of preventing nerve injury. PMID:25206452

Experimental study of hemodynamics in the circle of willis

PubMed Central

2015-01-01

Background The Circle of Willis (CoW) is an important collateral pathway of the cerebral blood flow. An experimental study of the cerebral blood flow (CBF) distribution in different anatomical variations may help to a better understanding of the collateral mechanism of the CoW. Methods An in-vitro test rig was developed to simulate the physiological cerebral blood flow in the CoW. Ten anatomical variations were considered in this study, include a set of different degrees of stenosis in L-ICA and L-ICA occlusion coexist with common anatomical variations. Volume flow rates of efferent arteries and pressure signals at the end of communicating arteries of each case were recorded. Physiological pressure waveforms were applied as inlet boundary condition. Results In the development of L-ICA stenosis, the total CBF decreases with the increase of stenosis degree. The blood supply of ipsilateral middle cerebral artery (MCA) was affected most by the stenosis of L-ICA. Anterior communicating artery (ACoA) and ipsilateral posterior communicating artery (PCoA) function as important collateral pathways of cerebral collateral circulation when unilateral stenosis occurred. The blood supply of anterior cerebral circulation was compensated by the posterior cerebral circulation through ipsilateral PCoA when L-ICA stenosis degree is greater than 40% and the affected side was compensated immediately by the unaffected side through ACoA. Blood flow of the anterior circulation and the total CBF reached the minimum among all cases studied when L-ICA occlusion coexist with the absence of PCoA. Conclusion The results demonstrated the flow distribution patterns of the CoW under anatomical variations and clarified the collateral mechanism of the CoW. The flow ACoA is the most sensitive indexes to the morphology change of ipsilateral ICA. The relative independence of the circulation in anterior and posterior sections of the CoW is not broken and the function of ipsilateral PCoA is not activated until a severe stenosis of unilateral ICA occurs. PCoA is the most important collateral pathway of the collateral circulation and the missing of PCoA has the highest risk of stroke when the ipsilateral ICA has severe stenosis. These findings may provide the basis for future therapeutic and diagnosis applications. PMID:25603138

Variant Inferior Alveolar Nerves and Implications for Local Anesthesia

PubMed Central

Wolf, Kevin T.; Brokaw, Everett J.; Bell, Andrea; Joy, Anita

2016-01-01

A sound knowledge of anatomical variations that could be encountered during surgical procedures is helpful in avoiding surgical complications. The current article details anomalous morphology of inferior alveolar nerves encountered during routine dissection of the craniofacial region in the Gross Anatomy laboratory. We also report variations of the lingual nerves, associated with the inferior alveolar nerves. The variations were documented and a thorough review of literature was carried out. We focus on the variations themselves, and the clinical implications that these variations present. Thorough understanding of variant anatomy of the lingual and inferior alveolar nerves may determine the success of procedural anesthesia, the etiology of pathologic processes, and the avoidance of surgical misadventure. PMID:27269666

The maxillary second molar - anatomical variations (case report).

PubMed

Beshkenadze, E; Chipashvili, N

2015-01-01

To be acquainted with dental anatomical specificity is of great importance for dental endodontic treatment algorithm. The subject of present publication is 2 clinical cases of upper second molars, detailed characterization of, which is considered very important for enrichment of anatomical knowledge about dental anatomical variations. In one case, the reason for admission to the clinic of a 38-year-old woman was complains as of esthetic character as well as functional misbalance (disturbance of chewing function due to the damage of orthopedic construction). The patient indicated to the existence of coronary defects of large size aesthetic discomforts, damage and discolouration of old orthopedic construction (denture) in maxillary right molar area. According to the data obtained after clinical and visiographical examinations, chronic periodontitis of 17 teeth was identified as a result of incomplete endodontic treatment. According to the data obtained after clinical and visiographical examinations, the diagnosis of chronic periodontitis of 17 teeth was identified, tooth 17 with 2 roots and 2 canals. In the second clinical case, the reason for admission to the clinic of a 39-year-old woman was severe pain in the upper right molar area. The patient indicated to the caries on the tooth 17. After completion of proper survey clinical and visiographical examinations, acute pulpitis (K04.00) - with three roots and 4 canals was diagnosed. In both cases after the proper examinations and agreement with the patients a treatment plan envisaging: 17 teeth endodontic treatment, filling of caries defects and their preparation on one hand for orthopedic construction (denture) and on the other hand for restoration of anatomical integrity by light-cured composite, was scheduled. The present study is designed to prevent complications of endodontic treatment of the second molar, to optimize diagnosis and treatment algorithm, once again proving reliable information indicating to the individuality of treatment tactics.

A Feature-based Developmental Model of the Infant Brain in Structural MRI

PubMed Central

Toews, Matthew; Wells, William M.; Zöllei, Lilla

2014-01-01

In this paper, anatomical development is modeled as a collection of distinctive image patterns localized in space and time. A Bayesian posterior probability is defined over a random variable of subject age, conditioned on data in the form of scale-invariant image features. The model is automatically learned from a large set of images exhibiting significant variation, used to discover anatomical structure related to age and development, and fit to new images to predict age. The model is applied to a set of 230 infant structural MRIs of 92 subjects acquired at multiple sites over an age range of 8-590 days. Experiments demonstrate that the model can be used to identify age-related anatomical structure, and to predict the age of new subjects with an average error of 72 days. PMID:23286050

[Histo-anatomical researches of two subspecies of Lavandula angustifolia Mill].

PubMed

Robu, Silvia; Galeş, Ramona; Toma, C; Stănescu, Ursula

2011-01-01

The structure of the inflorescences of two subspecies of Lavandula angustifolia sL. angustifolia ssp. angustifolia and. L. angustifolia ssp. pyrenaica (D.C.) Guineaţ was studied to determine the range of variation in certain histo-anatomical characters. The flower and leaf structure has been analysed on cross and superficial section using the usual techniques and methods applied in plant histo-anatomical research. In cross-section, inflorescence axis has a squared-shape contour, with four proeminent ribs. On the epiderme of inflorescence axis there are present stomata, trichoms and secretory hairs. The trichoms are pluricelullar and T-branched. The secretory hairs have a short pedicel and a uni-or bicellular head. The study revealed that there are only quantitative differences, referring to the degree of sclerification and lignification of mechanical elements and the size of the vascular bundles.

Microvascular Decompression for Classical Trigeminal Neuralgia Caused by Venous Compression: Novel Anatomic Classifications and Surgical Strategy.

PubMed

Wu, Min; Fu, Xianming; Ji, Ying; Ding, Wanhai; Deng, Dali; Wang, Yehan; Jiang, Xiaofeng; Niu, Chaoshi

2018-05-01

Microvascular decompression of the trigeminal nerve is the most effective treatment for trigeminal neuralgia. However, when encountering classical trigeminal neuralgia caused by venous compression, the procedure becomes much more difficult, and failure or recurrence because of incomplete decompression may become frequent. This study aimed to investigate the anatomic variation of the culprit veins and discuss the surgical strategy for different types. We performed a retrospective analysis of 64 consecutive cases in whom veins were considered as responsible vessels alone or combined with other adjacent arteries. The study classified culprit veins according to operative anatomy and designed personalized approaches and decompression management according to different forms of compressive veins. Curative effects were assessed by the Barrow Neurological Institute (BNI) pain intensity score and BNI facial numbness score. The most commonly encountered veins were the superior petrosal venous complex (SPVC), which was artificially divided into 4 types according to both venous tributary distribution and empty point site. We synthetically considered these factors and selected an approach to expose the trigeminal root entry zone, including the suprafloccular transhorizontal fissure approach and infratentorial supracerebellar approach. The methods of decompression consist of interposing and transposing by using Teflon, and sometimes with the aid of medical adhesive. Nerve combing (NC) of the trigeminal root was conducted in situations of extremely difficult neurovascular compression, instead of sacrificing veins. Pain completely disappeared in 51 patients, and the excellent outcome rate was 79.7%. There were 13 patients with pain relief treated with reoperation. Postoperative complications included 10 cases of facial numbness, 1 case of intracranial infection, and 1 case of high-frequency hearing loss. The accuracy recognition of anatomic variation of the SPVC is crucial for the management of classical trigeminal neuralgia caused by venous compression. Selecting an appropriate approach and using reasonable decompression methods can bring complete postoperative pain relief for most cases. NC can be an alternative choice for extremely difficult cases, but it could lead to facial numbness more frequently. Copyright © 2018 Elsevier Inc. All rights reserved.

Prospective regularization design in prior-image-based reconstruction

NASA Astrophysics Data System (ADS)

Dang, Hao; Siewerdsen, Jeffrey H.; Webster Stayman, J.

2015-12-01

Prior-image-based reconstruction (PIBR) methods leveraging patient-specific anatomical information from previous imaging studies and/or sequences have demonstrated dramatic improvements in dose utilization and image quality for low-fidelity data. However, a proper balance of information from the prior images and information from the measurements is required (e.g. through careful tuning of regularization parameters). Inappropriate selection of reconstruction parameters can lead to detrimental effects including false structures and failure to improve image quality. Traditional methods based on heuristics are subject to error and sub-optimal solutions, while exhaustive searches require a large number of computationally intensive image reconstructions. In this work, we propose a novel method that prospectively estimates the optimal amount of prior image information for accurate admission of specific anatomical changes in PIBR without performing full image reconstructions. This method leverages an analytical approximation to the implicitly defined PIBR estimator, and introduces a predictive performance metric leveraging this analytical form and knowledge of a particular presumed anatomical change whose accurate reconstruction is sought. Additionally, since model-based PIBR approaches tend to be space-variant, a spatially varying prior image strength map is proposed to optimally admit changes everywhere in the image (eliminating the need to know change locations a priori). Studies were conducted in both an ellipse phantom and a realistic thorax phantom emulating a lung nodule surveillance scenario. The proposed method demonstrated accurate estimation of the optimal prior image strength while achieving a substantial computational speedup (about a factor of 20) compared to traditional exhaustive search. Moreover, the use of the proposed prior strength map in PIBR demonstrated accurate reconstruction of anatomical changes without foreknowledge of change locations in phantoms where the optimal parameters vary spatially by an order of magnitude or more. In a series of studies designed to explore potential unknowns associated with accurate PIBR, optimal prior image strength was found to vary with attenuation differences associated with anatomical change but exhibited only small variations as a function of the shape and size of the change. The results suggest that, given a target change attenuation, prospective patient-, change-, and data-specific customization of the prior image strength can be performed to ensure reliable reconstruction of specific anatomical changes.

Rapid Communication: Effect of machine, anatomical location, and replication on instrumental color of boneless pork loins.

PubMed

Barkley, K E; Fields, B; Dilger, A C; Boler, D D

2018-06-07

The objective was to determine the effect of machine, anatomical location and replication (multiple readings) on instrumental color and to characterize the amount of variation each factor contributed to overall color. Instrumental color was measured 3 times on the anterior and 3 times on the posterior end of 250 pork loins with 2 different Minolta CR-400 Chroma meter devices. Each Minolta was programed to use a D65 illuminant, 2º observer with an 8 mm aperture, and calibrated with white tiles specific to each machine. Therefore, a total of 12 instrumental color measurements were collected on each loin. The VARCOMP procedure in SAS was used to estimate the proportion of variation contributed by each factor to CIE L*, a*, b*, chroma and hue. Based on previous research, the average untrained consumer is able to distinguish between 3-L* units, 0.4-a* units, and 0.9-hue angle units. Loins evaluated with machine 1 were 0.71 L* units darker (P < 0.01), 1.09 b* units more yellow (P < 0.01), 0.47 chroma units more saturated (P < 0.01), and had a hue angle 5.12 units greater (P < 0.01) than when evaluated with machine 2 but did not differ (P = 0.24) in redness. The anterior portion of the loin was lighter, less red, more yellow, more saturated and had a greater hue angle than the posterior end (P < 0.01). All color trait values decreased (P < 0.01) as replication number increased. Inherent color differences among loins contributed the greatest proportion of variability for lightness (58%), redness (57%), yellowness (70%), saturation (70%) and hue angle (49%). Machine contributed 1% variability to lightness 3% to saturation, 23% to yellowness and 31% to hue angle (31%) but did not contribute to variability for redness. Anatomical location contributed 41% to lightness, 43% to redness, 7% to yellowness, 27% to saturation and 31% to hue angle. Replication did not contribute to total variation for any color traits, even though it did differ among measurements. Overall, there were differences in instrumental color values between the two machines tested but those differences were likely less than the threshold for detection by a consumer. Even so, inherent color differences between loins were a greater contributor to total variability than the differences between the 2 machines. Therefore, it is more important to define the location of measurements than replication or machine when using a Minolta CR-400 when performing color evaluations, assuming the settings are the same.

Anatomic variations of the renal vessels: focus on the precaval right renal artery.

PubMed

Bouali, Ourdia; Labarre, David; Molinier, François; Lopez, Raphaël; Benouaich, Vincent; Lauwers, Frédéric; Moscovici, Jacques

2012-07-01

The aim of this study was to determine the prevalence of precaval right renal artery and to investigate the distribution of renal arteries and veins. We discuss a theory of development of renal vascular variants. We retrospectively reviewed 120 arterial phase contrast material-enhanced spiral computerized tomography scans of the abdomen (1- to 2-mm section thickness) performed during a two-month period. Forty percent of the study group (48 patients) had one artery and one vein on each side, with typical course. There was a 9.17% prevalence of precaval right renal artery: 10 patients had a lower pole accessory artery in precaval position and one patient had the main and the accessory arteries that pass anterior to the inferior vena cava. In these cases, associated variations of renal vessels were higher than in the patients without precaval artery variant. There were multiple arteries in 28.3% of the right kidneys and in 26.7% of the left ones. Variants of the right renal vein consisted in multiple veins in 20% (24 cases). We detected no case of multiple left renal veins, but we described variations of its course (circum- or retroaortic vein) in 9.17% (11 cases). Twenty-six patients (21.7%) had associated variations of the renal pedicle. The current technical support allows for a minimally invasive study of vessels anatomy. In our study the prevalence of a precaval right renal artery appears to be higher than previously reported (9.17%). Knowledge on anatomical variations of right renal artery and associated renal vessels variations has major clinical implications.

Anatomy of the capsulolabral complex and rotator interval related to glenohumeral instability.

PubMed

Itoigawa, Yoshiaki; Itoi, Eiji

2016-02-01

The glenohumeral joint with instability is a common diagnosis that often requires surgery. The aim of this review was to present an overview of the anatomy of the glenohumeral joint with emphasis on instability based on the current literature and to describe the detailed anatomy and anatomical variants of the glenohumeral joint associated with anterior and posterior shoulder instability. A review was performed using PubMed/MEDLINE using key words: Search terms were "glenohumeral", "shoulder instability", "cadaver", "rotator interval", "anatomy", and "anatomical study". During the last decade, the interest in both arthroscopic repair techniques and surgical anatomy of the glenohumeral ligament (superior, middle, and inferior), labrum, and rotator interval has increased. Understanding of the rotator interval and attachment of the inferior glenohumeral ligament on the glenoid or humeral head have evolved significantly. The knowledge of the detailed anatomy and anatomical variations is essential for the surgeon in order to understand the pathology, make a correct diagnosis of instability, and select proper treatment options. Proper understanding of anatomical variants can help us avoid misdiagnosis. Level of evidence V.

Development of a new generation of high-resolution anatomical models for medical device evaluation: the Virtual Population 3.0

NASA Astrophysics Data System (ADS)

Gosselin, Marie-Christine; Neufeld, Esra; Moser, Heidi; Huber, Eveline; Farcito, Silvia; Gerber, Livia; Jedensjö, Maria; Hilber, Isabel; Di Gennaro, Fabienne; Lloyd, Bryn; Cherubini, Emilio; Szczerba, Dominik; Kainz, Wolfgang; Kuster, Niels

2014-09-01

The Virtual Family computational whole-body anatomical human models were originally developed for electromagnetic (EM) exposure evaluations, in particular to study how absorption of radiofrequency radiation from external sources depends on anatomy. However, the models immediately garnered much broader interest and are now applied by over 300 research groups, many from medical applications research fields. In a first step, the Virtual Family was expanded to the Virtual Population to provide considerably broader population coverage with the inclusion of models of both sexes ranging in age from 5 to 84 years old. Although these models have proven to be invaluable for EM dosimetry, it became evident that significantly enhanced models are needed for reliable effectiveness and safety evaluations of diagnostic and therapeutic applications, including medical implants safety. This paper describes the research and development performed to obtain anatomical models that meet the requirements necessary for medical implant safety assessment applications. These include implementation of quality control procedures, re-segmentation at higher resolution, more-consistent tissue assignments, enhanced surface processing and numerous anatomical refinements. Several tools were developed to enhance the functionality of the models, including discretization tools, posing tools to expand the posture space covered, and multiple morphing tools, e.g., to develop pathological models or variations of existing ones. A comprehensive tissue properties database was compiled to complement the library of models. The results are a set of anatomically independent, accurate, and detailed models with smooth, yet feature-rich and topologically conforming surfaces. The models are therefore suited for the creation of unstructured meshes, and the possible applications of the models are extended to a wider range of solvers and physics. The impact of these improvements is shown for the MRI exposure of an adult woman with an orthopedic spinal implant. Future developments include the functionalization of the models for specific physical and physiological modeling tasks.

Subject-specific longitudinal shape analysis by coupling spatiotemporal shape modeling with medial analysis

NASA Astrophysics Data System (ADS)

Hong, Sungmin; Fishbaugh, James; Rezanejad, Morteza; Siddiqi, Kaleem; Johnson, Hans; Paulsen, Jane; Kim, Eun Young; Gerig, Guido

2017-02-01

Modeling subject-specific shape change is one of the most important challenges in longitudinal shape analysis of disease progression. Whereas anatomical change over time can be a function of normal aging, anatomy can also be impacted by disease related degeneration. Anatomical shape change may also be affected by structural changes from neighboring shapes, which may cause non-linear variations in pose. In this paper, we propose a framework to analyze disease related shape changes by coupling extrinsic modeling of the ambient anatomical space via spatiotemporal deformations with intrinsic shape properties from medial surface analysis. We compare intrinsic shape properties of a subject-specific shape trajectory to a normative 4D shape atlas representing normal aging to isolate shape changes related to disease. The spatiotemporal shape modeling establishes inter/intra subject anatomical correspondence, which in turn enables comparisons between subjects and the 4D shape atlas, and also quantitative analysis of disease related shape change. The medial surface analysis captures intrinsic shape properties related to local patterns of deformation. The proposed framework jointly models extrinsic longitudinal shape changes in the ambient anatomical space, as well as intrinsic shape properties to give localized measurements of degeneration. Six high risk subjects and six controls are randomly sampled from a Huntington's disease image database for qualitative and quantitative comparison.

ANATOMICAL RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT OF THE KNEE: DOUBLE BAND OR SINGLE BAND?

PubMed

Zanella, Luiz Antonio Zanotelli; Junior, Adair Bervig; Badotti, Augusto Alves; Michelin, Alexandre Froes; Algarve, Rodrigo Ilha; de Quadros Martins, Cesar Antonio

2012-01-01

To evaluate the double-band and single-band techniques for anatomical reconstruction of the anterior cruciate ligament of the knee and demonstrate that the double-band technique not only provides greater anterior stability but also causes less pain and a better subjective patient response. We selected 42 patients who underwent anterior cruciate ligament reconstruction, by means of either the single-band anatomical reconstruction technique, using flexor tendon grafts with two tunnels, or the double-band anatomical reconstruction technique, using four tunnels and grafts from the semitendinosus and gracilis tendons. All fixations were performed using interference screws. There was no variation in the sample. Before the operation, the objective and subjective IKDC scores, Lysholm score and length of time with the injury were evaluated. All these variables were reassessed six months later, and the KT-1000 correlation with the contralateral knee was also evaluated. There was no significant difference between the two groups in subjective evaluations, but the single-band group showed better results in relation to range of motion and objective evaluations including KT-1000 (with statistical significance). Our study demonstrated that there was no difference between the two groups in subjective evaluations, but better results were found using the single-band anatomical technique, in relation to objective evaluations.

ANATOMICAL RECONSTRUCTION OF ANTERIOR CRUCIATE LIGAMENT OF THE KNEE: DOUBLE BAND OR SINGLE BAND?

PubMed Central

Zanella, Luiz Antonio Zanotelli; Junior, Adair Bervig; Badotti, Augusto Alves; Michelin, Alexandre Froes; Algarve, Rodrigo Ilha; de Quadros Martins, Cesar Antonio

2015-01-01

Objective: To evaluate the double-band and single-band techniques for anatomical reconstruction of the anterior cruciate ligament of the knee and demonstrate that the double-band technique not only provides greater anterior stability but also causes less pain and a better subjective patient response. Methods: We selected 42 patients who underwent anterior cruciate ligament reconstruction, by means of either the single-band anatomical reconstruction technique, using flexor tendon grafts with two tunnels, or the double-band anatomical reconstruction technique, using four tunnels and grafts from the semitendinosus and gracilis tendons. All fixations were performed using interference screws. There was no variation in the sample. Before the operation, the objective and subjective IKDC scores, Lysholm score and length of time with the injury were evaluated. All these variables were reassessed six months later, and the KT-1000 correlation with the contralateral knee was also evaluated. Results: There was no significant difference between the two groups in subjective evaluations, but the single-band group showed better results in relation to range of motion and objective evaluations including KT-1000 (with statistical significance). Conclusion: Our study demonstrated that there was no difference between the two groups in subjective evaluations, but better results were found using the single-band anatomical technique, in relation to objective evaluations. PMID:27042621

Evaluation of morpho-anatomical and chemical differences between varieties of the medicinal plant Casearia sylvestris Swartz.

PubMed

Claudino, Josiane C; Sacramento, Luis V S do; Koch, Ingrid; Santos, Helen A; Cavalheiro, Alberto J; Tininis, Aristeu G; Santos, André G dos

2013-01-01

Casearia sylvestris Swartz (Salicaceae) has been used in traditional medicine and its leaf extracts have been exhibited important pharmacological activities. The species presents morphological, chemical and genetic variation. Two varieties are considered due external morphological differences: C. sylvestris var. sylvestris and var. lingua. There are difficulties in definition of these varieties. The objective of this work is to evaluate chemical and morpho-anatomical differences between C. sylvestris varieties that can be applied in their distinction for pharmaceutical or botanical purposes. Transverse and paradermic sections of leaves were prepared for morpho-anatomical, histochemical and quantitative microscopy (stomatal and palisade index) analyses. Diterpene profiles of the specimens were obtained by HPLC-DAD and TLC. Morpho-anatomical analyses demonstrated significant differences between the varieties only in paradermic sections: var. sylvestris--polygonal epidermic cell walls and hypostomatic; var. lingua--rounded epidermic cell walls and amphistomatic. No differences were observed for stomatal index; palisade index was found 2.8 for var. lingua and 3.9 for var. sylvestris. Chromatographic analyses confirmed previous results demonstrating that diterpene profile in varieties differs, with predominance of these metabolites in var. sylvestris. In conclusion, this work indicates that chromatographic analysis besides morpho-anatomical analysis can be applied in distinction of C. sylvestris varieties.

Endodontic management of mesiobuccal-2 canal in four-rooted and five-canalled mandibular third molar.

PubMed

Garg, Amit Kumar; Bhardwaj, Anuj; Mantri, Vijay R; Agrawal, Neha

2014-05-01

A case of unusual Root morphology is presented to demonstrate anatomic variations in mandibular third molar. The most common configuration of mandibular third molar is two Roots and three canals; however they may have many different combinations. Endodontic treatment was performed in mandibular third molar having aberrant anatomy. Four Root canal orifices were located with the aid of dental operating microscope (DOM) and three separate Roots were diagnosed with radiographs. Spiral computed tomography (SCT) showed the presence of an extra canal and extra Root, indicating a rare anatomic configuration. Looking for additional canals and Roots are important part of successful endodontics, as the knowledge of their existence enable clinicians to treat a case successfully that otherwise might end in failure. The use of DOM and SCT in this case greatly contributed toward making a confirmatory diagnosis and successful endodontic treatment of four-rooted and five-canalled mandibular third molar. Variation in Root canal anatomy is very common. Knowledge of these variations is very essential for successful Root canal outcome, inability to do so can lead to missed canals and failures. Hence, thorough knowledge of Root canal anatomy and advances in diagnostic aids are essential.

Morphologic variations of maxillary molars palatal root and the importance of its knowledge for endodontic practice: a case series.

PubMed

Scarparo, Roberta Kochenborger; Pereira, Leticia; Moro, Diana; Grundling, Grasiela; Gomes, Maximiliano; Grecca, Fabiana Soares

2011-03-01

The present report describes and discusses root canal variations in the internal morphology of maxillary molars. Dental internal anatomy is directly related to all the technical stages of the endodontic treatment. Even though, in some situations a typical anatomical characteristics can be faced, and the professional should be able to identify them. This clinical report describes five cases with different pulpar and periapical diagnostics where the endodontic treatment was performed, in which during the treatment the unusual occurrence of two or three canals in the palatal root 'or even two distinct palatal roots' of first and second maxillary molars, were described and important details for achieving treatment success were discussed. The knowledge of tooth internal anatomy must be considered during clinical and radiographic examinations. This should be valued not only to find atypical canals but also to enable calcified canals cleaning and shaping, once they are frequently omitted during endodontic therapy. Anatomic variations can occur in any tooth, and palatal roots of maxillary first and second molars are no exception. The complexity of the root canal system and the importance of identifying its internal anatomy for planning endodontic treatment increase the chances of success.

Comparative study on skin dose measurement using MOSFET and TLD for pediatric patients with acute lymphatic leukemia.

PubMed

Al-Mohammed, Huda I; Mahyoub, Fareed H; Moftah, Belal A

2010-07-01

The object of this study was to compare the difference of skin dose measured in patients with acute lymphatic leukemia (ALL) treated with total body irradiation (TBI) using metal oxide semiconductor field-effect transistors (mobile MOSFET dose verification system (TN-RD-70-W) and thermoluminescent dosimeters (TLD-100 chips, Harshaw/ Bicron, OH, USA). Because TLD has been the most-commonly used technique in the skin dose measurement of TBI, the aim of the present study is to prove the benefit of using the mobile MOSFET (metal oxide semiconductor field effect transistor) dosimeter, for entrance dose measurements during the total body irradiation (TBI) over thermoluminescent dosimeters (TLD). The measurements involved 10 pediatric patients ages between 3 and 14 years. Thermoluminescent dosimeters and MOSFET dosimetry were performed at 9 different anatomic sites on each patient. The present results show there is a variation between skin dose measured with MOSFET and TLD in all patients, and for every anatomic site selected, there is no significant difference in the dose delivered using MOSFET as compared to the prescribed dose. However, there is a significant difference for every anatomic site using TLD compared with either the prescribed dose or MOSFET. The results indicate that the dosimeter measurements using the MOSFET gave precise measurements of prescribed dose. However, TLD measurement showed significant increased skin dose of cGy as compared to either prescribed dose or MOSFET group. MOSFET dosimeters provide superior dose accuracy for skin dose measurement in TBI as compared with TLD.

Short-term UV-B exposure induces metabolic and anatomical changes in peel of harvested lemons contributing in fruit protection against green mold.

PubMed

Ruiz, V E; Interdonato, R; Cerioni, L; Albornoz, P; Ramallo, J; Prado, F E; Hilal, M; Rapisarda, V A

2016-06-01

UV-B radiation (UVBR) is a small fraction of the solar spectrum from 280 to 315nm. UVBR produces photomorphogenic acclimation responses in plants, modulating their cellular structure and physiology. Here, changes in the peel of harvested lemons after short time exposure to UVBR were analyzed and its potential effects against fungal infection were studied. In the flavedo, UVBR treatment induced variations in the respiratory profiles and increased the phenolic compound contents. Final products of the flavonoid pathway (flavones, flavonols and anthocyanins) increased more markedly than their precursors (flavanones and dihydroflavonols). The increased accumulation of soluble phenolics in the flavedo of treated lemons is associated with the high antioxidant activity found in the flavedo of these samples. Supporting the biochemical determinations, anatomical observations showed abundant intravacuolar deposits of phenolic compounds and an increase in the cell wall thickness in UVBR-treated samples. Metabolic and anatomical modifications associated to UVBR improved natural defenses against Penicillium digitatum, the causal agent of green mold disease. Our results suggest that mature postharvest lemons exposed to the artificial radiation showed phenotypic plasticity, allowing an acclimation response to UVBR which confers fruit resistance to pathogens. Thus, combination of UVBR with other treatments could represent an important improvement to control postharvest diseases on citrus. Copyright © 2016 Elsevier B.V. All rights reserved.

Simulating video-assisted thoracoscopic lobectomy: a virtual reality cognitive task simulation.

PubMed

Solomon, Brian; Bizekis, Costas; Dellis, Sophia L; Donington, Jessica S; Oliker, Aaron; Balsam, Leora B; Zervos, Michael; Galloway, Aubrey C; Pass, Harvey; Grossi, Eugene A

2011-01-01

Current video-assisted thoracoscopic surgery training models rely on animals or mannequins to teach procedural skills. These approaches lack inherent teaching/testing capability and are limited by cost, anatomic variations, and single use. In response, we hypothesized that video-assisted thoracoscopic surgery right upper lobe resection could be simulated in a virtual reality environment with commercial software. An anatomy explorer (Maya [Autodesk Inc, San Rafael, Calif] models of the chest and hilar structures) and simulation engine were adapted. Design goals included freedom of port placement, incorporation of well-known anatomic variants, teaching and testing modes, haptic feedback for the dissection, ability to perform the anatomic divisions, and a portable platform. Preexisting commercial models did not provide sufficient surgical detail, and extensive modeling modifications were required. Video-assisted thoracoscopic surgery right upper lobe resection simulation is initiated with a random vein and artery variation. The trainee proceeds in a teaching or testing mode. A knowledge database currently includes 13 anatomic identifications and 20 high-yield lung cancer learning points. The "patient" is presented in the left lateral decubitus position. After initial camera port placement, the endoscopic view is displayed and the thoracoscope is manipulated via the haptic device. The thoracoscope port can be relocated; additional ports are placed using an external "operating room" view. Unrestricted endoscopic exploration of the thorax is allowed. An endo-dissector tool allows for hilar dissection, and a virtual stapling device divides structures. The trainee's performance is reported. A virtual reality cognitive task simulation can overcome the deficiencies of existing training models. Performance scoring is being validated as we assess this simulator for cognitive and technical surgical education. Copyright © 2011. Published by Mosby, Inc.

ZebraBeat: a flexible platform for the analysis of the cardiac rate in zebrafish embryos

NASA Astrophysics Data System (ADS)

de Luca, Elisa; Zaccaria, Gian Maria; Hadhoud, Marwa; Rizzo, Giovanna; Ponzini, Raffaele; Morbiducci, Umberto; Santoro, Massimo Mattia

2014-05-01

Heartbeat measurement is important in assesssing cardiac function because variations in heart rhythm can be the cause as well as an effect of hidden pathological heart conditions. Zebrafish (Danio rerio) has emerged as one of the most useful model organisms for cardiac research. Indeed, the zebrafish heart is easily accessible for optical analyses without conducting invasive procedures and shows anatomical similarity to the human heart. In this study, we present a non-invasive, simple, cost-effective process to quantify the heartbeat in embryonic zebrafish. To achieve reproducibility, high throughput and flexibility (i.e., adaptability to any existing confocal microscope system and with a user-friendly interface that can be easily used by researchers), we implemented this method within a software program. We show here that this platform, called ZebraBeat, can successfully detect heart rate variations in embryonic zebrafish at various developmental stages, and it can record cardiac rate fluctuations induced by factors such as temperature and genetic- and chemical-induced alterations. Applications of this methodology may include the screening of chemical libraries affecting heart rhythm and the identification of heart rhythm variations in mutants from large-scale forward genetic screens.

SU-E-J-127: Real-Time Dosimetric Assessment for Adaptive Head-And-Neck Treatment Via A GPU-Based Deformable Image Registration Framework

DOE Office of Scientific and Technical Information (OSTI.GOV)

Qi, S; Neylon, J; Chen, A

2014-06-01

Purposes: To systematically monitor anatomic variations and their dosimetric consequences during head-and-neck (H'N) radiation therapy using a GPU-based deformable image registration (DIR) framework. Methods: Eleven H'N IMRT patients comprised the subject population. The daily megavoltage CT and weekly kVCT scans were acquired for each patient. The pre-treatment CTs were automatically registered with their corresponding planning CT through an in-house GPU-based DIR framework. The deformation of each contoured structure was computed to account for non-rigid change in the patient setup. The Jacobian determinant for the PTVs and critical structures was used to quantify anatomical volume changes. Dose accumulation was performed tomore » determine the actual delivered dose and dose accumulation. A landmark tool was developed to determine the uncertainty in the dose distribution due to registration error. Results: Dramatic interfraction anatomic changes leading to dosimetric variations were observed. During the treatment courses of 6–7 weeks, the parotid gland volumes changed up to 34.7%, the center-of-mass displacement of the two parotids varied in the range of 0.9–8.8mm. Mean doses were within 5% and 3% of the planned mean doses for all PTVs and CTVs, respectively. The cumulative minimum/mean/EUD doses were lower than the planned doses by 18%, 2%, and 7%, respectively for the PTV1. The ratio of the averaged cumulative cord maximum doses to the plan was 1.06±0.15. The cumulative mean doses assessed by the weekly kVCTs were significantly higher than the planned dose for the left-parotid (p=0.03) and right-parotid gland (p=0.006). The computation time was nearly real-time (∼ 45 seconds) for registering each pre-treatment CT to the planning CT and dose accumulation with registration accuracy (for kVCT) at sub-voxel level (<1.5mm). Conclusions: Real-time assessment of anatomic and dosimetric variations is feasible using the GPU-based DIR framework. Clinical implementation of this technology may enable timely plan adaption and potentially lead to improved outcome.« less

Anatomical relations of anterior and posterior ankle arthroscopy portals: a cadaveric study.

PubMed

Oliva, Xavier Martin; Méndez López, José Manuel; Monzo Planella, Mariano; Bravo, Alex; Rodrigues-Pinto, Ricardo

2015-04-01

Ankle arthroscopy is an increasingly used technique. Knowledge of the anatomical structures in relation to its portals is paramount to avoid complications. Twenty cadaveric ankles were analysed to assess the distance between relevant neurovascular structures to the anteromedial, anterolateral, posteromedial, and posterolateral arthroscopy portals. The intermediate dorsal branch of the superficial peroneal nerve was the closest structure to any of the portals (4.8 mm from the anterolateral portal), followed by the posterior tibial nerve (7.3 mm from the posteromedial portal). All structures analysed but one (posterior tibial artery) were, at least in one specimen, <5 mm distant from one of the portals. This study provides information on the anatomical relations of ankle arthroscopy portals and relevant neurovascular structures, confirming previous studies identifying the superficial peroneal nerve as the structure at highest risk of injury, but also highlighting some important variations. Techniques to minimise the injury to these structures are discussed.

Arthroscopic approach and anatomy of the hip.

PubMed

Aprato, Alessandro; Giachino, Matteo; Masse, Alessandro

2016-01-01

Hip arthroscopy has gained popularity among the orthopedic community and a precise assessment of indications, techniques and results is constantly brought on. In this chapter the principal standard entry portals for central and peripheral compartment are discussed. The description starts from the superficial landmarks for portals placement and continues with the deep layers. For each entry point an illustration of the main structures encountered is provided and the principal structures at risk for different portals are accurately examined. Articular anatomical description is carried out from the arthroscope point of view and sub-divided into central and peripheral compartment. The two compartments are systematically analyzed and the accessible articular areas for each portal explained. Moreover, some anatomical variations that can be found in the normal hip are reported. The anatomical knowledge of the hip joint along with a precise notion of the structures encountered with the arthroscope is an essential requirement for a secure and successful surgery. Level of evidence: V.

A systematic review of variations of the recurrent laryngeal nerve.

PubMed

Ling, Xing Yao; Smoll, Nicolas Roydon

2016-01-01

With thyroid cancer fast becoming one of the most common endocrine cancers, the frequency of thyroid surgery has increased. A common and debilitating concern with thyroid surgery is recurrent laryngeal nerve (RLN) paralysis leading to glottal obstruction and airway compromise. A systematic review regarding the anatomical variation of the recurrent laryngeal nerve was performed to determine the position of anatomical variants of the RLN in relation to the inferior thyroid artery (ITA) as well as the prevalence of nonrecurrent laryngeal nerve (NRLN). MEDLINE, Web of Science, MEDITEXT, AMED, CINAHL, Cochrane, ProQuest, Pubmed, and ScienceDirect. Databases were searched using the search terms "inferior thyroid artery," "recurrent laryngeal nerve," "nonrecurrent laryngeal nerve," and "anatomical variation." The reference sections of the articles found were searched for additional reports. The references of all articles were searched to find articles missed in the database search. A total of 8,655 RLN sides were included in this study. One thousand eight hundred and thirteen (20.95%; 95% confidence interval (CI) 20.09, 2,182) showed a Type A configuration of RLN in relation to the ITA, 2,432 (28.10%; 95% CI 27.15, 29.06) showed a Type B configuration and 4,410 (50.95%; 95% CI 49.89, 52.01) showed a Type C configuration between the RLN and the ITA. The second search returned with 38,568 recurrent laryngeal sides and only 221 (0.57%; 95%CI 0.5, 0.65) NRLN documented. The RLN is most commonly found in the posterior position, relative to the ITA. The incidence of the NRLN is low, only occurring in 0.57% of people. © 2015 Wiley Periodicals, Inc.

[Anatomical strategies of Henle trunk in laparoscopic right hemi-colectomy for right colon cancer].

PubMed

Feng, Bo; Yan, Xialin; Zhang, Sen; Xue, Pei; He, Zirui; Zheng, Minhua

2017-06-25

The advancement of laparoscopic surgery serves as a trigger for better understanding of the vascular structure at the inferior border of the pancreas, especially Henle trunk. Henle trunk was first found as convergence to superior mesenteric vein (SMV) conjoined by sub-right colon vein (SRCV) and right gastroepiploic vein (RGEV), but decades later, anterior superior pancreatic duodenal vein (ASPDV) was described as another conjoint vein of Henle trunk. These tributaries are the basic elements of Henle trunk in early years' study. A proper surgical procedure for Henle trunk can significantly reduce the complications of radical right hemi-colectomy (Japanese D3 resection and European complete mesocolic excision, CME). There are four variations of Henle trunk according to the colic venous tributaries that consists the anatomic variations in transverse colon posterior space(TRCPS). These variations are like "fingerprint and pattern" of CME. The recognition and extension of the TRCS is the key to the dissection of Henle trunk in laparoscopic right hemi-colectomy. Our medical center proposed four feasible approaches for extension:(1) hybrid medial approach; (2) completely medial approach; (3)completely medial access by "page-turning" approach; (4) completely medial approach along RCV. Mostly, RCV ended in Henle trunk, and completely medial approach along RCV is efficient to identify the Henle trunk in CME. We suggest dissecting the inferior margin of pancreas along SMV in a bottom-to-top fashion, followed by the dissection of middle colic vessels to reveal the root of Henle trunk. And it's better to dissect Henle trunk by branch rather than at its root for safety. Here, we describe the anatomic characters of Henles trunk, the surgical approach and strategies of Henle trunk in laparoscopic surgery.

Quantification and Visualization of Variation in Anatomical Trees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amenta, Nina; Datar, Manasi; Dirksen, Asger

This paper presents two approaches to quantifying and visualizing variation in datasets of trees. The first approach localizes subtrees in which significant population differences are found through hypothesis testing and sparse classifiers on subtree features. The second approach visualizes the global metric structure of datasets through low-distortion embedding into hyperbolic planes in the style of multidimensional scaling. A case study is made on a dataset of airway trees in relation to Chronic Obstructive Pulmonary Disease.

Maxillary first molar with five canals

PubMed Central

Umer, Fahad

2014-01-01

Root canal treatment is a technically demanding procedure especially in the case of maxillary first molar where the anatomy is extremely variable. Failure to recognise and treat these variations may lead to unpredictable outcomes. This case report describes non-surgical endodontic treatment of a maxillary first molar with two palatal and two mesiobuccal canals. It also highlights the need for good anatomical knowledge of root canal morphology and its variations in order to achieve consistently successful results. PMID:25239993

Anatomical study of prefixed versus postfixed brachial plexuses in adult human cadaver.

PubMed

Guday, Edengenet; Bekele, Asegedech; Muche, Abebe

2017-05-01

The brachial plexus is usually formed by the fusion of anterior primary rami of the fifth to eighth cervical and the first thoracic spinal nerves. Variations in the formation of the brachial plexus may occur. Variations in brachial plexus anatomy are important to radiologists, surgeons and anaesthesiologists performing surgical procedures in the neck, axilla and upper limb regions. These variations may lead to deviation from the expected dermatome distribution as well as differences in the motor innervation of muscles of the upper limb. This study is aimed to describe the anatomical variations of brachial plexus in its formation among 20 Ethiopian cadavers. Observational based study was conducted by using 20 cadavers obtained from the Department of Human Anatomy at University of Gondar, Bahir Dar, Addis Ababa, Hawasa, Hayat Medical College and St Paul Hospital Millennium Medical College. Data analysis was conducted using thematic approaches. A total of 20 cadavers examined bilaterally for the formation of brachial plexus. Of the 40 sides, 30 sides (75%) were found normal, seven sides (17.5%) prefixed, three sides (7.5%) postfixed and one side of the cadaver lacks cord formation. The brachial plexus formation in most subjects is found to be normal. Among the variants, the numbers of the prefixed brachial plexuses are greater than the postfixed brachial plexuses. © 2016 Royal Australasian College of Surgeons.

Anatomical variation of arterial supply to the rabbit stomach.

PubMed

Ikegami, Reona; Tanimoto, Yoshimasa; Kishimoto, Miori; Shibata, Hideshi

2016-05-03

Gastric stasis is common in rabbits, and gastrotomy may be performed to cure this pathological condition. Detailed descriptions of the arterial supply to the stomach are essential for this surgical operation, but published descriptions are limited. Here, we investigated anatomical variations of the arterial supply to the stomach in 43 New Zealand White rabbits by injecting colored latex into arteries. We observed that the left gastric artery that arose as the second branch from the celiac artery provided 1-3 parietal and 1-3 visceral branches to the stomach, with various branching patterns depending on the case. In 34 of 43 cases, the left gastric artery ended upon entering the gastric wall at the lesser curvature, whereas in the remaining cases, the artery continued as the hepatic artery without entering the gastric wall. The right gastric artery that branched off from the gastroduodenal artery also supplied the lesser curvature sinistrally but did not anastomose with the left gastric artery. In 40 cases, the hepatic artery provided 1-4 pyloric branches. In the fundic region, the short gastric arteries arose from the splenic artery and varied in number from 2 to 6. The right and left gastroepiploic arteries anastomosed to give 2-7 branches to the greater curvature. The results showed that many variations occurred in the arteries supplying the rabbit stomach, suggesting that such variations should be considered when performing veterinary surgical treatments in rabbits.

Reflective journals: unmasking student perceptions of anatomical education.

PubMed

Lazarus, L; Sookrajh, R; Satyapal, K S

2017-01-01

In medical education, reflection has been considered to be a core skill in professional competence. The anatomy laboratory is an ideal setting for faculty/ student interaction and provides invaluable opportunities for active learning and reflection on anatomical knowledge. This study was designed to record student attitudes regarding human cadaveric dissection, explore their experiences of anatomy through an analysis of their journal-reflective writings and determine whether this type of creative writing had a beneficial effect on those students who chose to complete them. A total of 75 journals from Medical and Allied Health Science students were collected and analysed. Results were categorised according to the following themes: (i) Dissecting room stressors (27.6%); (ii) Educational value of dissection (26.3%); (iii) Appreciation, Gratitude, Respect and Curiosity for the cadaver (18.9%); (iv) Positive and negative sentiments expressed in the dissecting room (25.8%); (v) Benefit of alternate teaching modalities (4.6%); (vi) Spirituality/Religious Beliefs (3.7%); (vii) Shared humanity and emotional bonds (3.69%); (viii) Acknowledgement of human anatomical variations (3.2%); (ix) Beauty and complexity of the human body (1.8%) and (x) Psychological detachment (0.9%). Students appreciated the opportunity to share their emotions and reflect on the humanistic dimension of anatomy as a subject. Student reflections illustrated clearly their thoughts and some of the difficult issues with which they wrestled. The anatomy laboratory is seen as the budding clinician's first encounter with a patient, albeit a cadaver. This was the first time that reflective journals were given to students in the discipline. Reflective journals allow students to express themselves in an open-ended and creative fashion. It also assists students to integrate anatomy and clinical medicine and assists in applying their basic anatomical knowledge in an authentic, yet safe environment.

Robust Estimation of Electron Density From Anatomic Magnetic Resonance Imaging of the Brain Using a Unifying Multi-Atlas Approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren, Shangjie; Department of Radiation Oncology, Stanford University School of Medicine, Palo Alto, California; Hara, Wendy

Purpose: To develop a reliable method to estimate electron density based on anatomic magnetic resonance imaging (MRI) of the brain. Methods and Materials: We proposed a unifying multi-atlas approach for electron density estimation based on standard T1- and T2-weighted MRI. First, a composite atlas was constructed through a voxelwise matching process using multiple atlases, with the goal of mitigating effects of inherent anatomic variations between patients. Next we computed for each voxel 2 kinds of conditional probabilities: (1) electron density given its image intensity on T1- and T2-weighted MR images; and (2) electron density given its spatial location in a referencemore » anatomy, obtained by deformable image registration. These were combined into a unifying posterior probability density function using the Bayesian formalism, which provided the optimal estimates for electron density. We evaluated the method on 10 patients using leave-one-patient-out cross-validation. Receiver operating characteristic analyses for detecting different tissue types were performed. Results: The proposed method significantly reduced the errors in electron density estimation, with a mean absolute Hounsfield unit error of 119, compared with 140 and 144 (P<.0001) using conventional T1-weighted intensity and geometry-based approaches, respectively. For detection of bony anatomy, the proposed method achieved an 89% area under the curve, 86% sensitivity, 88% specificity, and 90% accuracy, which improved upon intensity and geometry-based approaches (area under the curve: 79% and 80%, respectively). Conclusion: The proposed multi-atlas approach provides robust electron density estimation and bone detection based on anatomic MRI. If validated on a larger population, our work could enable the use of MRI as a primary modality for radiation treatment planning.« less

Local setup errors in image-guided radiotherapy for head and neck cancer patients immobilized with a custom-made device.

PubMed

Giske, Kristina; Stoiber, Eva M; Schwarz, Michael; Stoll, Armin; Muenter, Marc W; Timke, Carmen; Roeder, Falk; Debus, Juergen; Huber, Peter E; Thieke, Christian; Bendl, Rolf

2011-06-01

To evaluate the local positioning uncertainties during fractionated radiotherapy of head-and-neck cancer patients immobilized using a custom-made fixation device and discuss the effect of possible patient correction strategies for these uncertainties. A total of 45 head-and-neck patients underwent regular control computed tomography scanning using an in-room computed tomography scanner. The local and global positioning variations of all patients were evaluated by applying a rigid registration algorithm. One bounding box around the complete target volume and nine local registration boxes containing relevant anatomic structures were introduced. The resulting uncertainties for a stereotactic setup and the deformations referenced to one anatomic local registration box were determined. Local deformations of the patients immobilized using our custom-made device were compared with previously published results. Several patient positioning correction strategies were simulated, and the residual local uncertainties were calculated. The patient anatomy in the stereotactic setup showed local systematic positioning deviations of 1-4 mm. The deformations referenced to a particular anatomic local registration box were similar to the reported deformations assessed from patients immobilized with commercially available Aquaplast masks. A global correction, including the rotational error compensation, decreased the remaining local translational errors. Depending on the chosen patient positioning strategy, the remaining local uncertainties varied considerably. Local deformations in head-and-neck patients occur even if an elaborate, custom-made patient fixation method is used. A rotational error correction decreased the required margins considerably. None of the considered correction strategies achieved perfect alignment. Therefore, weighting of anatomic subregions to obtain the optimal correction vector should be investigated in the future. Copyright © 2011 Elsevier Inc. All rights reserved.

Quantitative cardiac SPECT reconstruction with reduced image degradation due to patient anatomy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsui, B.M.W.; Zhao, X.D.; Gregoriou, G.K.

1994-12-01

Patient anatomy has complicated effects on cardiac SPECT images. The authors investigated reconstruction methods which substantially reduced these effects for improved image quality. A 3D mathematical cardiac-torso (MCAT) phantom which models the anatomical structures in the thorax region were used in the study. The phantom was modified to simulate variations in patient anatomy including regions of natural thinning along the myocardium, body size, diaphragmatic shape, gender, and size and shape of breasts for female patients. Distributions of attenuation coefficients and Tl-201 uptake in different organs in a normal patient were also simulated. Emission projection data were generated from the phantomsmore » including effects of attenuation and detector response. The authors have observed the attenuation-induced artifacts caused by patient anatomy in the conventional FBP reconstructed images. Accurate attenuation compensation using iterative reconstruction algorithms and attenuation maps substantially reduced the image artifacts and improved quantitative accuracy. They conclude that reconstruction methods which accurately compensate for non-uniform attenuation can substantially reduce image degradation caused by variations in patient anatomy in cardiac SPECT.« less

Brain tissues atrophy is not always the best structural biomarker of physiological aging: A multimodal cross-sectional study.

PubMed

Cherubini, Andrea; Caligiuri, Maria Eugenia; Péran, Patrice; Sabatini, Umberto; Cosentino, Carlo; Amato, Francesco

2015-01-01

This study presents a voxel-based multiple regression analysis of different magnetic resonance image modalities, including anatomical T1-weighted, T2* relaxometry, and diffusion tensor imaging. Quantitative parameters sensitive to complementary brain tissue alterations, including morphometric atrophy, mineralization, microstructural damage, and anisotropy loss, were compared in a linear physiological aging model in 140 healthy subjects (range 20-74 years). The performance of different predictors and the identification of the best biomarker of age-induced structural variation were compared without a priori anatomical knowledge. The best quantitative predictors in several brain regions were iron deposition and microstructural damage, rather than macroscopic tissue atrophy. Age variations were best resolved with a combination of markers, suggesting that multiple predictors better capture age-induced tissue alterations. These findings highlight the importance of a combined evaluation of multimodal biomarkers for the study of aging and point to a number of novel applications for the method described.

Evaluation of living liver transplant donors: method for precise anatomic definition by using a dedicated contrast-enhanced MR imaging protocol.

PubMed

Sahani, Dushyant; D'souza, Roy; Kadavigere, Rajagopal; Hertl, Martin; McGowan, Jennifer; Saini, Sanjay; Mueller, Peter R

2004-01-01

Liver transplantation from a living donor involves removal of part of the donor liver in a fashion that does not endanger its vascular supply or metabolic function. The radiologist plays an important role in evaluation of the living donor to define the conditions under which graft donation is contraindicated and to identify anatomic variations that may alter the surgical approach. In the past, diagnostic work-up of the donor involved costly and invasive tests. Currently, dynamic contrast material-enhanced computed tomography and magnetic resonance (MR) imaging are the imaging tests performed, each of which has advantages and limitations. MR imaging performed with liver-specific and extravascular contrast agents may be used as a single imaging test for comprehensive noninvasive evaluation of living liver transplant donors. MR imaging provides valuable information about variations in the vascular and biliary anatomy and allows evaluation of the hepatic parenchyma for diffuse or focal abnormalities. Copyright RSNA, 2004

Importance of Multimodal MRI in Characterizing Brain Tissue and Its Potential Application for Individual Age Prediction.

PubMed

Cherubini, Andrea; Caligiuri, Maria Eugenia; Peran, Patrice; Sabatini, Umberto; Cosentino, Carlo; Amato, Francesco

2016-09-01

This study presents a voxel-based multiple regression analysis of different magnetic resonance image modalities, including anatomical T1-weighted, T2(*) relaxometry, and diffusion tensor imaging. Quantitative parameters sensitive to complementary brain tissue alterations, including morphometric atrophy, mineralization, microstructural damage, and anisotropy loss, were compared in a linear physiological aging model in 140 healthy subjects (range 20-74 years). The performance of different predictors and the identification of the best biomarker of age-induced structural variation were compared without a priori anatomical knowledge. The best quantitative predictors in several brain regions were iron deposition and microstructural damage, rather than macroscopic tissue atrophy. Age variations were best resolved with a combination of markers, suggesting that multiple predictors better capture age-induced tissue alterations. The results of the linear model were used to predict apparent age in different regions of individual brain. This approach pointed to a number of novel applications that could potentially help highlighting areas particularly vulnerable to disease.

Systematic significance of midrib vascular bundles in some Schefflera Spreng (Araliaceae) species

NASA Astrophysics Data System (ADS)

Noor-Syaheera, M. Y.; Noraini, T.; Aida-Shafreena, A. P.

2014-09-01

Anatomy study was undertaken on midrib vascular bundles of six Schefflera Spreng species, namely as S. obovatilimba, S. borneensis, S.kinabaluensis, S.lineamentorum, S. opacus and S.petiolosa. The genus Schefflera belongs to the family Araliaceae. The objective of this study is to determine variations in the midrib anatomical characteristics that can be used to identify species. Leaves samples were collected from various forest reserves in Sabah and Sarawak, Malaysia., were fixed in AA (Acetic acid: Alcohol, in a ratio of 1:3), the midrib parts then were sectioned using sliding microtome, were stained in Safranin and Alcian blue, been mounted in Eupharal and were observed under light microscope. Findings in this study have shown that all species have complex structure of vascular bundles. Each species has identical arrangement of vascular bundles and can be very useful for species identification. As a conclusion, variation in the midrib anatomical characteristics is outstanding and can has taxonomic value in the genus Schefflera respectively.

Anatomical nuances of the internal carotid artery in relation to the quadrangular space.

PubMed

Dolci, Ricardo L L; Ditzel Filho, Leo F S; Goulart, Carlos R; Upadhyay, Smita; Buohliqah, Lamia; Lazarini, Paulo R; Prevedello, Daniel M; Carrau, Ricardo L

2018-01-01

OBJECTIVE The aim of this study was to evaluate the anatomical variations of the internal carotid artery (ICA) in relation to the quadrangular space (QS) and to propose a classification system based on the results. METHODS A total of 44 human cadaveric specimens were dissected endonasally under direct endoscopic visualization. During the dissection, the anatomical variations of the ICA and their relationship with the QS were noted. RESULTS The space between the paraclival ICAs (i.e., intercarotid space) can be classified as 1 of 3 different shapes (i.e., trapezoid, square, or hourglass) based on the trajectory of the ICAs. The ICA trajectories also directly influence the volumetric area of the QS. Based on its geometry, the QS was classified as one of the following: 1) Type A has the smallest QS area and is associated with a trapezoid intercarotid space, 2) Type B corresponds to the expected QS area (not minimized or enlarged) and is associated with a square intercarotid space, and 3) Type C has the largest QS area and is associated with an hourglass intercarotid space. CONCLUSIONS The different trajectories of the ICAs can modify the area of the QS and may be an essential parameter to consider for preoperative planning and defining the most appropriate corridor to reach Meckel's cave. In addition, ICA trajectories should be considered prior to surgery to avoid injuring the vessels.

Contribution of the computed tomography of the anatomical aspects of the sphenoid sinuses to forensic identification.

PubMed

Auffret, Mathieu; Garetier, Marc; Diallo, Idris; Aho, Serge; Ben Salem, Douraied

2016-12-01

Body identification is the cornerstone of forensic investigation. It can be performed using radiographic techniques, if antemortem images are available. This study was designed to assess the value of visual comparison of the computed tomography (CT) anatomical aspects of the sphenoid sinuses, in forensic individual identification, especially if antemortem dental records, fingerprints or DNA samples are not available. This retrospective work took place in a French university hospital. The supervisor of this study randomly selected from the picture archiving and communication system (PACS), 58 patients who underwent one (16 patients) or two (42 patients) head CT in various neurological contexts. To avoid bias, those studies were prepared (anonymized, and all the head structures but the sphenoid sinuses were excluded), and used to constitute two working lists of 50 (42+8) CT studies of the sphenoid sinuses. An anatomical classification system of the sphenoid sinuses anatomical variations was created based on the anatomical and surgical literature. In these two working lists, three blinded readers had to identify, using the anatomical system and subjective visual comparison, 42 pairs of matched studies, and 16 unmatched studies. Readers were blinded from the exact numbers of matching studies. Each reader correctly identified the 42 pairs of CT with a concordance of 100% [97.5% confidence interval: 91-100%], and the 16 unmatched CT with a concordance of 100% [97.5% confidence interval: 79-100%]. Overall accuracy was 100%. Our study shows that establishing the anatomical concordance of the sphenoid sinuses by visual comparison could be used in personal identification. This easy method, based on a frequently and increasingly prescribed exam, still needs to be assessed on a postmortem cohort. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The Missed Inferior Alveolar Block: A New Look at an Old Problem

PubMed Central

Milles, Maano

1984-01-01

A variation of a previously described technique to obtain mandibular block anesthesia is presented. This technique varies from those previously described in that is uses palpable anatomic landmarks, both extra- and intraoral, to orient the placement of the needle. This technique relies on several readily observed landmarks and the integration of these landmarks. Because palpable landmarks are used, consistent results can be easily obtained even in patients who present with a wide variety of anatomical variances which otherwise make this injection technique difficult and prone to failure. ImagesFigure 1Figure 3Figure 4Figure 5Figure 6 PMID:6597690

Maxillary First Molars with 2 Distobuccal Canals: A Case Series.

PubMed

Fogel, Howard M; Cunha, Rodrigo Sanches

2017-11-01

An appreciation of the anatomic complexity of the root canal system is essential at every step of endodontic treatment. Endodontic treatment of teeth with unusual root canal anatomy presents a unique challenge. Eight patients underwent nonsurgical root canal treatment of 3-rooted maxillary first molars in a specialty endodontic private practice. Four cases of Weine type II and 4 cases of Weine type III canal configurations in the distobuccal root of maxillary first molars were presented.This article highlighted an uncommon anatomic variation of 2 canals in the distobuccal root of the maxillary first molar. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Anomalous Origin of the Left Vertebral Artery from the Aortic Arch

PubMed Central

Einstein, Evan H.; Song, Linda H.; Villela, Natalia L. A.; Fasani-Feldberg, Gregory B.; Jacobs, Jonathan L.; Kim, Dolly O.; Nathawat, Akshay; Patel, Devika; Bender, Roger B.; Peters, Daniel F.

2016-01-01

Anatomic anomalies of the aortic arch have implications for clinical practice if their significance is understood. Our case study involves a cadaveric finding of the left vertebral artery originating directly from the aortic arch. Although this anatomical variation has been documented, the prevalence of this anomaly may be generally underestimated. After noting this anomaly, we analyzed 27 cases and found that four female cadavers had the left vertebral artery originating from the aortic arch rather than the left subclavian artery. With a prevalence rate of 14.8%, it would seem that this anomaly is more significant than previously thought, which could have implications for surgical practice. PMID:27757404

Anomalous Origin of the Left Vertebral Artery from the Aortic Arch.

PubMed

Einstein, Evan H; Song, Linda H; Villela, Natalia L A; Fasani-Feldberg, Gregory B; Jacobs, Jonathan L; Kim, Dolly O; Nathawat, Akshay; Patel, Devika; Bender, Roger B; Peters, Daniel F

2016-04-01

Anatomic anomalies of the aortic arch have implications for clinical practice if their significance is understood. Our case study involves a cadaveric finding of the left vertebral artery originating directly from the aortic arch. Although this anatomical variation has been documented, the prevalence of this anomaly may be generally underestimated. After noting this anomaly, we analyzed 27 cases and found that four female cadavers had the left vertebral artery originating from the aortic arch rather than the left subclavian artery. With a prevalence rate of 14.8%, it would seem that this anomaly is more significant than previously thought, which could have implications for surgical practice.

Unusual anatomy of a maxillary first molar with two palatal roots: a case report.

PubMed

Tomazinho, Flávia S F; Baratto-Filho, Flares; Zaitter, Suellen; Leonardi, Denise P; Gonzaga, Carla C

2010-03-01

The success of endodontic therapy is based on good endodontic access, correct cleaning and shaping, and adequate root canal obturation. However, endodontic treatment is also dependent on a sound knowledge of the internal anatomy of human teeth, especially when anatomical variations are present. Certain anatomical changes may be present to varying degrees, and it is important to report these to improve the understanding and expertise of endodontic specialists. With this aim in mind, this study reports an example of a maxillary first molar showing unusual anatomy (four roots and six root canals) and describes the endodontic treatment that was employed.

Deformable templates guided discriminative models for robust 3D brain MRI segmentation.

PubMed

Liu, Cheng-Yi; Iglesias, Juan Eugenio; Tu, Zhuowen

2013-10-01

Automatically segmenting anatomical structures from 3D brain MRI images is an important task in neuroimaging. One major challenge is to design and learn effective image models accounting for the large variability in anatomy and data acquisition protocols. A deformable template is a type of generative model that attempts to explicitly match an input image with a template (atlas), and thus, they are robust against global intensity changes. On the other hand, discriminative models combine local image features to capture complex image patterns. In this paper, we propose a robust brain image segmentation algorithm that fuses together deformable templates and informative features. It takes advantage of the adaptation capability of the generative model and the classification power of the discriminative models. The proposed algorithm achieves both robustness and efficiency, and can be used to segment brain MRI images with large anatomical variations. We perform an extensive experimental study on four datasets of T1-weighted brain MRI data from different sources (1,082 MRI scans in total) and observe consistent improvement over the state-of-the-art systems.

Size and shape variations of the bony components of sperm whale cochleae.

PubMed

Schnitzler, Joseph G; Frédérich, Bruno; Früchtnicht, Sven; Schaffeld, Tobias; Baltzer, Johannes; Ruser, Andreas; Siebert, Ursula

2017-04-25

Several mass strandings of sperm whales occurred in the North Sea during January and February 2016. Twelve animals were necropsied and sampled around 48 h after their discovery on German coasts of Schleswig Holstein. The present study aims to explore the morphological variation of the primary sensory organ of sperm whales, the left and right auditory system, using high-resolution computerised tomography imaging. We performed a quantitative analysis of size and shape of cochleae using landmark-based geometric morphometrics to reveal inter-individual anatomical variations. A hierarchical cluster analysis based on thirty-one external morphometric characters classified these 12 individuals in two stranding clusters. A relative amount of shape variation could be attributable to geographical differences among stranding locations and clusters. Our geometric data allowed the discrimination of distinct bachelor schools among sperm whales that stranded on German coasts. We argue that the cochleae are individually shaped, varying greatly in dimensions and that the intra-specific variation observed in the morphology of the cochleae may partially reflect their affiliation to their bachelor school. There are increasing concerns about the impact of noise on cetaceans and describing the auditory periphery of odontocetes is a key conservation issue to further assess the effect of noise pollution.

Talar anchor placement for modified Brostrom lateral ankle stabilization procedure.

PubMed

Angirasa, Arush K; Barrett, Michael J

2008-01-01

The modified Brostrom procedure has been a proven procedure with excellent utility in the treatment of lateral ankle instability within limitation. Multiple variations of the original technique have been described in the literature to date. Included in these variations are differences in anchor placement, suture technique, or both. In this research study, we propose placing a bone screw anchor into the lateral shoulder of the talus rather than the typical placement at the lateral malleolus for anatomic reconstruction of the lateral ankle ligaments.

The Lateral Meniscus as a Guide to Anatomical Tibial Tunnel Placement During Anterior Cruciate Ligament Reconstruction.

PubMed

Kassam, A M; Tillotson, L; Schranz, P J; Mandalia, V I

2015-01-01

The aim of the study is to show, on an MRI scan, that the posterior border of the anterior horn of the lateral meniscus (AHLM) could guide tibial tunnel position in the sagittal plane and provide anatomical graft position. One hundred MRI scans were analysed with normal cruciate ligaments and no evidence of meniscal injury. We measured the distance between the posterior border of the AHLM and the midpoint of the ACL by superimposing sagittal images. The mean distance between the posterior border of the AHLM and the ACL midpoint was -0.1mm (i.e. 0.1mm posterior to the ACL midpoint). The range was 5mm to -4.6mm. The median value was 0.0mm. 95% confidence interval was from -0.5 to 0.3mm. A normal, parametric distribution was observed and Intra- and inter-observer variability showed significant correlation (p<0.05) using Pearsons Correlation test (intra-observer) and Interclass correlation (inter-observer). Using the posterior border of the AHLM is a reproducible and anatomical marker for the midpoint of the ACL footprint in the majority of cases. It can be used intra-operatively as a guide for tibial tunnel insertion and graft placement allowing anatomical reconstruction. There will inevitably be some anatomical variation. Pre-operative MRI assessment of the relationship between AHLM and ACL footprint is advised to improve surgical planning. Level 4.

Intraspecific Variation in Wood Anatomical, Hydraulic, and Foliar Traits in Ten European Beech Provenances Differing in Growth Yield

PubMed Central

Hajek, Peter; Kurjak, Daniel; von Wühlisch, Georg; Delzon, Sylvain; Schuldt, Bernhard

2016-01-01

In angiosperms, many studies have described the inter-specific variability of hydraulic-related traits and little is known at the intra-specific level. This information is however mandatory to assess the adaptive capacities of tree populations in the context of increasing drought frequency and severity. Ten 20-year old European beech (Fagus sylvatica L.) provenances representing the entire distribution range throughout Europe and differing significantly in aboveground biomass increment (ABI) by a factor of up to four were investigated for branch wood anatomical, hydraulic, and foliar traits in a provenance trial located in Northern Europe. We quantified to which extend xylem hydraulic and leaf traits are under genetic control and tested whether the xylem hydraulic properties (hydraulic efficiency and safety) trades off with yield and wood anatomical and leaf traits. Our results showed that only three out of 22 investigated ecophysiological traits showed significant genetic differentiations between provenances, namely vessel density (VD), the xylem pressure causing 88% loss of hydraulic conductance and mean leaf size. Depending of the ecophysiological traits measured, genetic differentiation between populations explained 0–14% of total phenotypic variation, while intra-population variability was higher than inter-population variability. Most wood anatomical traits and some foliar traits were additionally related to the climate of provenance origin. The lumen to sapwood area ratio, vessel diameter, theoretical specific conductivity and theoretical leaf-specific conductivity as well as the C:N-ratio increased with climatic aridity at the place of origin while the carbon isotope signature (δ13C) decreased. Contrary to our assumption, none of the wood anatomical traits were related to embolism resistance but were strong determinants of hydraulic efficiency. Although ABI was associated with both VD and δ13C, both hydraulic efficiency and embolism resistance were unrelated, disproving the assumed trade-off between hydraulic efficiency and safety. European beech seems to compensate increasing water stress with growing size mainly by adjusting vessel number and not vessel diameter. In conclusion, European beech has a high potential capacity to cope with climate change due to the high degree of intra-population genetic variability. PMID:27379112

Intraspecific Variation in Wood Anatomical, Hydraulic, and Foliar Traits in Ten European Beech Provenances Differing in Growth Yield.

PubMed

Hajek, Peter; Kurjak, Daniel; von Wühlisch, Georg; Delzon, Sylvain; Schuldt, Bernhard

2016-01-01

In angiosperms, many studies have described the inter-specific variability of hydraulic-related traits and little is known at the intra-specific level. This information is however mandatory to assess the adaptive capacities of tree populations in the context of increasing drought frequency and severity. Ten 20-year old European beech (Fagus sylvatica L.) provenances representing the entire distribution range throughout Europe and differing significantly in aboveground biomass increment (ABI) by a factor of up to four were investigated for branch wood anatomical, hydraulic, and foliar traits in a provenance trial located in Northern Europe. We quantified to which extend xylem hydraulic and leaf traits are under genetic control and tested whether the xylem hydraulic properties (hydraulic efficiency and safety) trades off with yield and wood anatomical and leaf traits. Our results showed that only three out of 22 investigated ecophysiological traits showed significant genetic differentiations between provenances, namely vessel density (VD), the xylem pressure causing 88% loss of hydraulic conductance and mean leaf size. Depending of the ecophysiological traits measured, genetic differentiation between populations explained 0-14% of total phenotypic variation, while intra-population variability was higher than inter-population variability. Most wood anatomical traits and some foliar traits were additionally related to the climate of provenance origin. The lumen to sapwood area ratio, vessel diameter, theoretical specific conductivity and theoretical leaf-specific conductivity as well as the C:N-ratio increased with climatic aridity at the place of origin while the carbon isotope signature (δ(13)C) decreased. Contrary to our assumption, none of the wood anatomical traits were related to embolism resistance but were strong determinants of hydraulic efficiency. Although ABI was associated with both VD and δ(13)C, both hydraulic efficiency and embolism resistance were unrelated, disproving the assumed trade-off between hydraulic efficiency and safety. European beech seems to compensate increasing water stress with growing size mainly by adjusting vessel number and not vessel diameter. In conclusion, European beech has a high potential capacity to cope with climate change due to the high degree of intra-population genetic variability.

Representation and visualization of variability in a 3D anatomical atlas using the kidney as an example

NASA Astrophysics Data System (ADS)

Hacker, Silke; Handels, Heinz

2006-03-01

Computer-based 3D atlases allow an interactive exploration of the human body. However, in most cases such 3D atlases are derived from one single individual, and therefore do not regard the variability of anatomical structures concerning their shape and size. Since the geometric variability across humans plays an important role in many medical applications, our goal is to develop a framework of an anatomical atlas for representation and visualization of the variability of selected anatomical structures. The basis of the project presented is the VOXEL-MAN atlas of inner organs that was created from the Visible Human data set. For modeling anatomical shapes and their variability we utilize "m-reps" which allow a compact representation of anatomical objects on the basis of their skeletons. As an example we used a statistical model of the kidney that is based on 48 different variants. With the integration of a shape description into the VOXEL-MAN atlas it is now possible to query and visualize different shape variations of an organ, e.g. by specifying a person's age or gender. In addition to the representation of individual shape variants, the average shape of a population can be displayed. Besides a surface representation, a volume-based representation of the kidney's shape variants is also possible. It results from the deformation of the reference kidney of the volume-based model using the m-rep shape description. In this way a realistic visualization of the shape variants becomes possible, as well as the visualization of the organ's internal structures.

Physician opinions about an anatomy core curriculum: a case for medical imaging and vertical integration.

PubMed

Orsbon, Courtney P; Kaiser, Rebecca S; Ross, Callum F

2014-01-01

Pre-clinical anatomy curricula must provide medical students with the knowledge needed in a variety of medical and surgical specialties. But do physicians within specialties agree about what anatomical knowledge is most important in their practices? And, what is the common core of anatomical knowledge deemed essential by physicians in different specialties? Answers to these questions would be useful in designing pre-clinical anatomy courses. The primary aim of this study was to assess the importance of a human gross anatomy course by soliciting the opinions of physicians from a range of specialties. We surveyed 93 physicians to determine the importance of specific anatomical topics in their own practices. Their responses were analyzed to assess variation in intra- and inter-departmental attitudes toward the importance of anatomy. Nearly all of the topics taught in the course were deemed important by the clinicians as a group, but respondents showed little agreement on the rank order of importance of anatomical topics. Overall, only medical imaging received high importance by nearly all respondents, and lower importance was attached to embryology and lymphatic anatomy. Our survey data, however, also suggested distinct hierarchies in the importance assigned to anatomical topics within specialties. Given that physicians view the importance of anatomy differently, we suggest that students revisit anatomy through a vertically integrated curriculum tailored to provide specialty-specific anatomical training to advanced students based on their areas of clinical interest. Integration of medical imaging into pre-clinical anatomy courses, already underway in many medical schools, is of high clinical relevance. © 2013 American Association of Anatomists.

Fetal programming of reproduction, what we know and how we manage it

USDA-ARS?s Scientific Manuscript database

For the purposes of this paper, fetal programming will cover developmental and nutritional programming both before and after birth. Developmental programming is defined as changes in anatomical structure and/or physiology that result from differences in gene function instead of variation in DNA seq...

Effects of Instructional Strategies Using Cross Sections on the Recognition of Anatomical Structures in Correlated CT and MR Images

ERIC Educational Resources Information Center

Khalil, Mohammed K.; Paas, Fred; Johnson, Tristan E.; Su, Yung K.; Payer, Andrew F.

2008-01-01

This research is an effort to best utilize the interactive anatomical images for instructional purposes based on cognitive load theory. Three studies explored the differential effects of three computer-based instructional strategies that use anatomical cross-sections to enhance the interpretation of radiological images. These strategies include:…

A comparison of vowel normalization procedures for language variation research

NASA Astrophysics Data System (ADS)

Adank, Patti; Smits, Roel; van Hout, Roeland

2004-11-01

An evaluation of vowel normalization procedures for the purpose of studying language variation is presented. The procedures were compared on how effectively they (a) preserve phonemic information, (b) preserve information about the talker's regional background (or sociolinguistic information), and (c) minimize anatomical/physiological variation in acoustic representations of vowels. Recordings were made for 80 female talkers and 80 male talkers of Dutch. These talkers were stratified according to their gender and regional background. The normalization procedures were applied to measurements of the fundamental frequency and the first three formant frequencies for a large set of vowel tokens. The normalization procedures were evaluated through statistical pattern analysis. The results show that normalization procedures that use information across multiple vowels (``vowel-extrinsic'' information) to normalize a single vowel token performed better than those that include only information contained in the vowel token itself (``vowel-intrinsic'' information). Furthermore, the results show that normalization procedures that operate on individual formants performed better than those that use information across multiple formants (e.g., ``formant-extrinsic'' F2-F1). .

A comparison of vowel normalization procedures for language variation research.

PubMed

Adank, Patti; Smits, Roel; van Hout, Roeland

2004-11-01

An evaluation of vowel normalization procedures for the purpose of studying language variation is presented. The procedures were compared on how effectively they (a) preserve phonemic information, (b) preserve information about the talker's regional background (or sociolinguistic information), and (c) minimize anatomical/physiological variation in acoustic representations of vowels. Recordings were made for 80 female talkers and 80 male talkers of Dutch. These talkers were stratified according to their gender and regional background. The normalization procedures were applied to measurements of the fundamental frequency and the first three formant frequencies for a large set of vowel tokens. The normalization procedures were evaluated through statistical pattern analysis. The results show that normalization procedures that use information across multiple vowels ("vowel-extrinsic" information) to normalize a single vowel token performed better than those that include only information contained in the vowel token itself ("vowel-intrinsic" information). Furthermore, the results show that normalization procedures that operate on individual formants performed better than those that use information across multiple formants (e.g., "formant-extrinsic" F2-F1).

Midsagittal brain variation and MRI shape analysis of the precuneus in adult individuals.

PubMed

Bruner, Emiliano; Rangel de Lázaro, Gizéh; de la Cuétara, José Manuel; Martín-Loeches, Manuel; Colom, Roberto; Jacobs, Heidi I L

2014-04-01

Recent analyses indicate that the precuneus is one of the main centres of integration in terms of functional and structural processes within the human brain. This neuroanatomical element is formed by different subregions, involved in visuo-spatial integration, memory and self-awareness. We analysed the midsagittal brain shape in a sample of adult humans (n = 90) to evidence the patterns of variability and geometrical organization of this area. Interestingly, the major brain covariance pattern within adult humans is strictly associated with the relative proportions of the precuneus. Its morphology displays a marked individual variation, both in terms of geometry (mostly in its longitudinal dimensions) and anatomy (patterns of convolution). No patent differences are evident between males and females, and the allometric effect of size is minimal. However, in terms of morphology, the precuneus does not represent an individual module, being influenced by different neighbouring structures. Taking into consideration the apparent involvement of the precuneus in higher-order human brain functions and evolution, its wide variation further stresses the important role of these deep parietal areas in modern neuroanatomical organization. © 2014 Anatomical Society.

Aberrant Left Inferior Bronchial Artery Originating from the Left Gastric Artery in a Patient with Acute Massive Hemoptysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, Sen, E-mail: jasfly77@vip.163.com; Sun, Xi-Wen, E-mail: xwsun@citiz.net; Yu, Dong, E-mail: yudong_mail@126.com

Massive hemoptysis is a life-threatening condition, and the major source of bleeding in this condition is the bronchial circulation. Bronchial artery embolization is a safe and effective treatment for controlling hemoptysis. However, the sites of origin of the bronchial arteries (BAs) have numerous anatomical variations, which can result in a technical challenge to identify a bleeding artery. We present a rare case of a left inferior BA that originated from the left gastric artery in a patient with recurrent massive hemoptysis caused by bronchiectasis. The aberrant BA was embolized, and hemoptysis has been controlled for 8 months.

Coexistence of a pectoralis quartus muscle, a supernumerary head of biceps brachii muscle and an accessory head of flexor digitorum profundus muscle.

PubMed

Song, Halim; Kim, Jinu; Yoon, Sang-Pil

2018-05-26

Although anatomical variations in the upper limb are frequent, coexistence of multiple combined variations is rare. During a routine educational dissection at Jeju National University Medical School, three muscular variations were found in a 75-year-old Korean male cadaver, in which a supraclavicular cephalic vein was also found in ipsilateral upper extremity during skinning (Go et al., 2017). Here we describe characteristics of the pectoralis quartus muscle, the supernumerary head of biceps brachii muscle and an accessory head of flexor digitorum profundus muscle, and discuss their coexistence from morphological and embryological points of view.

Endoscopic sphenopalatine artery ligation for acute idiopathic epistaxis. Do anatomical variation and a limited evidence base raise questions regarding its place in management?

PubMed

Ellinas, A; Jervis, P; Kenyon, G; Flood, L M

2017-04-01

Endoscopic sphenopalatine artery ligation is widely accepted as effective and safe for acute spontaneous epistaxis that is unresponsive to conservative management. As with many new procedures, it has been progressively adopted as common practice, despite a limited evidence base for its efficacy. Early reviews called for comparative trials to support its adoption, but subsequent literature largely consists of case series and narrative reviews. These have attempted to derive an algorithm to establish its place in management, but consensus is still lacking. Intuitively, although there are theoretical objections, an operation regarded as relatively simple, fast and safe hardly seems to demand high-level evidence of efficacy. Rhinologists may be influenced by years of personal experience and success with the technique. However, estimates of the effect size and the added contribution to traditional surgical management are lacking. If the procedure could be shown to dramatically influence outcome, it should be standard practice and indispensable for all patients requiring operative intervention. This paper systematically examined the literature, appraising the anatomical basis for such an approach and evidence for its efficacy. It questions whether any units unable to consistently offer endoscopic sphenopalatine artery ligation should be undertaking surgical management of acute epistaxis.

The thoracic surface anatomy of adult black South Africans: A reappraisal from CT scans.

PubMed

Keough, N; Mirjalili, S A; Suleman, F E; Lockhat, Z I; van Schoor, A

2016-11-01

Surface landmarks or planes taught in anatomy curricula derive from standard anatomical textbooks. Although many surface landmarks are valid, clear age, sex, and population differences exist. We reappraise the thoracic surface anatomy of black South Africans. We analyzed 76 (female = 42; male = 34) thoracoabdominal CT-scans. Patients were placed in a supine position with arms abducted. We analyzed the surface anatomy of the sternal angle, tracheal, and pulmonary trunk bifurcation, azygos vein termination, central veins, heart apex, diaphragm, xiphisternal joint, and subcostal plane using standardized definitions. Surface anatomy landmarks were mostly within the normal variation limits described in previous studies. Variation was observed where the esophagus (T9) and inferior vena cava (IVC) (T8/T9/T10) passed through the diaphragm. The bifurcations of the trachea and pulmonary trunk were inferior to the sternal angle. The subcostal plane level was positioned at L1/L2. The origin of inferior mesenteric artery was mostly inferior to the subcostal plane. Sex differences were noted for the plane of the xiphisternal joint (P = 0.0082), with males (36%) intersecting at T10 and females (36%) intersecting at T9. We provide further evidence for population variations in surface anatomy. The clinical relevance of surface anatomical landmarks depends on descriptions of normal variation. Accurate descriptions of population, sex, age, and body type differences are essential. Clin. Anat. 29:1018-1024, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Reproducibility of retinal nerve fiber layer thickness measures using eye tracking in children with nonglaucomatous optic neuropathy.

PubMed

Rajjoub, Raneem D; Trimboli-Heidler, Carmelina; Packer, Roger J; Avery, Robert A

2015-01-01

To determine the intra- and intervisit reproducibility of circumpapillary retinal nerve fiber layer (RNFL) thickness measures using eye tracking-assisted spectral-domain optical coherence tomography (SD OCT) in children with nonglaucomatous optic neuropathy. Prospective longitudinal study. Circumpapillary RNFL thickness measures were acquired with SD OCT using the eye-tracking feature at 2 separate study visits. Children with normal and abnormal vision (visual acuity ≥ 0.2 logMAR above normal and/or visual field loss) who demonstrated clinical and radiographic stability were enrolled. Intra- and intervisit reproducibility was calculated for the global average and 9 anatomic sectors by calculating the coefficient of variation and intraclass correlation coefficient. Forty-two subjects (median age 8.6 years, range 3.9-18.2 years) met inclusion criteria and contributed 62 study eyes. Both the abnormal and normal vision cohort demonstrated the lowest intravisit coefficient of variation for the global RNFL thickness. Intervisit reproducibility remained good for those with normal and abnormal vision, although small but statistically significant increases in the coefficient of variation were observed for multiple anatomic sectors in both cohorts. The magnitude of visual acuity loss was significantly associated with the global (ß = 0.026, P < .01) and temporal sector coefficient of variation (ß = 0.099, P < .01). SD OCT with eye tracking demonstrates highly reproducible RNFL thickness measures. Subjects with vision loss demonstrate greater intra- and intervisit variability than those with normal vision. Copyright © 2015 Elsevier Inc. All rights reserved.

The right vertebral artery originating from the right occipital artery and the absence of the transverse foramen: a rare anatomical variation.

PubMed

Öner, Zülal; Öner, Serkan; Kahraman, Ayşegül Sağır

2017-12-01

Variations in the origin of the vertebral artery (VA) is a congenital anomaly that occurs during embryological development. Multiple variations related to VA origin have been reported in the literature. Abnormal VA origin is usually determined as incidental findings during angiographic or postmortem anatomical studies. Although most of the cases are asymptomatic, in patients with VA anomaly symptoms such as dizziness have been described. The anomalous variation in the origin of the right VA is rare and separated into three categories: (1) originating from the aorta, (2) originating from the carotid arteries, (3) duplicated origin. In this case, we aimed to present the right VA originating from the right occipital artery and concomitant anomalies of the transverse foramen that have not been reported previously according to our knowledge in literature. In a 32-year-old female patient referred to our hospital because of dizziness, the right VA was not observed on magnetic resonance imaging and computed tomography angiography (CTA) examination was performed. CTA showed hypoplasia of the right transverse foramen at the levels of the C1, C5 and C6 vertebrae and aplasia of the right transverse foramen at the levels of the C2, C3 and C4 vertebrae. The right VA originating from the right occipital artery continues to its normal course by entering the cranium through the foramen magnum at the level of the atlantooccipital junction.

Effects of plantation density on wood density and anatomical properties of red pine (Pinus resinosa Ait.)

Treesearch

J. Y. Zhu; C. Tim Scott; Karen L. Scallon; Gary C. Myers

2007-01-01

This study demonstrated that average ring width (or average annual radial growth rate) is a reliable parameter to quantify the effects of tree plantation density (growth suppression) on wood density and tracheid anatomical properties. The average ring width successfully correlated wood density and tracheid anatomical properties of red pines (Pinus resinosa Ait.) from a...

Crossing Anatomic Barriers-Transplantation of a Kidney with 5 Arteries, Duplication of the Pyelocalyceal System, and Double Ureter.

PubMed

Bachul, Piotr J; Osuch, Czesław; Chang, Ea-Sle; Bętkowska-Prokop, Alina; Pasternak, Artur; Szura, Mirosław; Matyja, Andrzej; Walocha, Jerzy A

2017-10-01

During the time of organ harvest, it is crucial for the kidney procurement team to consider significant vascular anatomical variations. Multiple renal arteries are not uncommon, and unintentional injury can result in an irreversibly damaged kidney graft that needs to be discarded. We present a kidney graft with 5 renal arteries and a single vein that was successfully procured and implanted with good graft function at discharge and at 4-yr follow-up. According to the literature, additional renal arteries can be found in about 33% of kidneys. This is the first study on a kidney with 5 arteries in the published literature, especially in the context of transplantation.

Intra-annual variability of anatomical structure and δ13C values within tree rings of spruce and pine in alpine, temperate and boreal Europe

PubMed Central

Vaganov, Eugene A.; Skomarkova, Marina V.; Knohl, Alexander; Brand, Willi A.; Roscher, Christiane

2009-01-01

Tree-ring width, wood density, anatomical structure and 13C/12C ratios expressed as δ13C-values of whole wood of Picea abies were investigated for trees growing in closed canopy forest stands. Samples were collected from the alpine Renon site in North Italy, the lowland Hainich site in Central Germany and the boreal Flakaliden site in North Sweden. In addition, Pinus cembra was studied at the alpine site and Pinus sylvestris at the boreal site. The density profiles of tree rings were measured using the DENDRO-2003 densitometer, δ13C was measured using high-resolution laser-ablation-combustion-gas chromatography-infra-red mass spectrometry and anatomical characteristics of tree rings (tracheid diameter, cell-wall thickness, cell-wall area and cell-lumen area) were measured using an image analyzer. Based on long-term statistics, climatic variables, such as temperature, precipitation, solar radiation and vapor pressure deficit, explained <20% of the variation in tree-ring width and wood density over consecutive years, while 29–58% of the variation in tree-ring width were explained by autocorrelation between tree rings. An intensive study of tree rings between 1999 and 2003 revealed that tree ring width and δ13C-values of whole wood were significantly correlated with length of the growing season, net radiation and vapor pressure deficit. The δ13C-values were not correlated with precipitation or temperature. A highly significant correlation was also found between δ13C of the early wood of one year and the late wood of the previous year, indicating a carry-over effect of the growing conditions of the previous season on current wood production. This latter effect may explain the high autocorrelation of long-term tree-ring statistics. The pattern, however, was complex, showing stepwise decreases as well as stepwise increases in the δ13C between late wood and early wood. The results are interpreted in the context of the biochemistry of wood formation and its linkage to storage products. It is clear that the relations between δ13C and tree-ring width and climate are multi-factorial in seasonal climates. PMID:19653008

"Dangerous" anatomic varieties of recurrent motor branch of median nerve.

PubMed

Elsaftawy, Ahmed; Gworys, Bohdan; Jabłecki, Jerzy; Szajerka, Tobiasz

2013-08-01

Carpal tunnel release became one of the most common operations in the field of hand surgery. Many controversies has been made about frequency of the so-called dangerous variations of motor branch of the median nerve. Knowledge of all the anatomical variations motor branches is the duty of every surgeon dealing with the subject. The aim of the study was to present the incidence of dangerous variants of median nerve motor branch in the carpal tunnel based on both clinical experience and anatomical studies performed on 20 cadaver wrists. Between 2006-2012 during minimally open carpal tunnel release we made photographic documentation of all visible dangerous varieties of recurrent motor branches of the median nerve. We also studied 20 cadaver wrists in the Department of Anatomy Medical University in Wrocław. Dangerous varieties of the motor branch of median nerve was found in three clinical cases and in one cadaver wrist. Also In one wrist we found one regular branche, which, however, has atypical two separate branches supplying the thenar muscles. Dangerous varieties of the motor branch of median nerve occur very rare in the population, but does not release from the fact that in each case special attention must be given.We also conclude that, at the minimally open carpal tunnel release procedure, the transverse carpal ligament should be released rather from the line of radial border of the 4th finger to minimize the risk of injury to the recurrent motor branch of median nerve.

Deformable torso phantoms of Chinese adults for personalized anatomy modelling.

PubMed

Wang, Hongkai; Sun, Xiaobang; Wu, Tongning; Li, Congsheng; Chen, Zhonghua; Liao, Meiying; Li, Mengci; Yan, Wen; Huang, Hui; Yang, Jia; Tan, Ziyu; Hui, Libo; Liu, Yue; Pan, Hang; Qu, Yue; Chen, Zhaofeng; Tan, Liwen; Yu, Lijuan; Shi, Hongcheng; Huo, Li; Zhang, Yanjun; Tang, Xin; Zhang, Shaoxiang; Liu, Changjian

2018-04-16

In recent years, there has been increasing demand for personalized anatomy modelling for medical and industrial applications, such as ergonomics device development, clinical radiological exposure simulation, biomechanics analysis, and 3D animation character design. In this study, we constructed deformable torso phantoms that can be deformed to match the personal anatomy of Chinese male and female adults. The phantoms were created based on a training set of 79 trunk computed tomography (CT) images (41 males and 38 females) from normal Chinese subjects. Major torso organs were segmented from the CT images, and the statistical shape model (SSM) approach was used to learn the inter-subject anatomical variations. To match the personal anatomy, the phantoms were registered to individual body surface scans or medical images using the active shape model method. The constructed SSM demonstrated anatomical variations in body height, fat quantity, respiratory status, organ geometry, male muscle size, and female breast size. The masses of the deformed phantom organs were consistent with Chinese population organ mass ranges. To validate the performance of personal anatomy modelling, the phantoms were registered to the body surface scan and CT images. The registration accuracy measured from 22 test CT images showed a median Dice coefficient over 0.85, a median volume recovery coefficient (RC vlm ) between 0.85 and 1.1, and a median averaged surface distance (ASD) < 1.5 mm. We hope these phantoms can serve as computational tools for personalized anatomy modelling for the research community. © 2018 Anatomical Society.

Advanced virtual endoscopy for endoscopic transsphenoidal pituitary surgery.

PubMed

Wolfsberger, Stefan; Neubauer, André; Bühler, Katja; Wegenkittl, Rainer; Czech, Thomas; Gentzsch, Stephan; Böcher-Schwarz, Hans-Gerd; Knosp, Engelbert

2006-11-01

Virtual endoscopy (vE) is the navigation of a camera through a virtual anatomical space that is computationally reconstructed from radiological image data. Inside this three-dimensional space, arbitrary movements and adaptations of viewing parameters are possible. Thereby, vE can be used for noninvasive diagnostic purposes and for simulation of surgical tasks. This article describes the development of an advanced system of vE for endoscopic transsphenoidal pituitary surgery and its application to teaching, training, and in the routine clinical setting. The vE system was applied to a series of 35 patients with pituitary pathology (32 adenomas, three Rathke's cleft cysts) operated endoscopically via the transsphenoidal route at the Department of Neurosurgery of the Medical University Vienna between 2004 and 2006. The virtual endoscopic images correlated well with the intraoperative view. For the transsphenoidal approach, vE improved intraoperative orientation by depicting anatomical landmarks and variations. For planning a safe and tailored opening of the sellar floor, transparent visualization of the pituitary adenoma and the normal gland in relation to the internal carotid arteries was useful. According to our experience, vE can be a valuable tool for endoscopic transsphenoidal pituitary surgery for training purposes and preoperative planning. For the novice, it can act as a simulator for endoscopic anatomy and for training surgical tasks. For the experienced pituitary surgeon, vE can depict the individual patient's anatomy, and may, therefore, improve intraoperative orientation. By prospectively visualizing unpredictable anatomical variations, vE may increase the safety of this surgical procedure.

Reproducibility Between Brain Uptake Ratio Using Anatomic Standardization and Patlak-Plot Methods.

PubMed

Shibutani, Takayuki; Onoguchi, Masahisa; Noguchi, Atsushi; Yamada, Tomoki; Tsuchihashi, Hiroko; Nakajima, Tadashi; Kinuya, Seigo

2015-12-01

The Patlak-plot and conventional methods of determining brain uptake ratio (BUR) have some problems with reproducibility. We formulated a method of determining BUR using anatomic standardization (BUR-AS) in a statistical parametric mapping algorithm to improve reproducibility. The objective of this study was to demonstrate the inter- and intraoperator reproducibility of mean cerebral blood flow as determined using BUR-AS in comparison to the conventional-BUR (BUR-C) and Patlak-plot methods. The images of 30 patients who underwent brain perfusion SPECT were retrospectively used in this study. The images were reconstructed using ordered-subset expectation maximization and processed using an automatic quantitative analysis for cerebral blood flow of ECD tool. The mean SPECT count was calculated from axial basal ganglia slices of the normal side (slices 31-40) drawn using a 3-dimensional stereotactic region-of-interest template after anatomic standardization. The mean cerebral blood flow was calculated from the mean SPECT count. Reproducibility was evaluated using coefficient of variation and Bland-Altman plotting. For both inter- and intraoperator reproducibility, the BUR-AS method had the lowest coefficient of variation and smallest error range about the Bland-Altman plot. Mean CBF obtained using the BUR-AS method had the highest reproducibility. Compared with the Patlak-plot and BUR-C methods, the BUR-AS method provides greater inter- and intraoperator reproducibility of cerebral blood flow measurement. © 2015 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Automatic Clustering and Thickness Measurement of Anatomical Variants of the Human Perirhinal Cortex

PubMed Central

Xie, Long; Pluta, John; Wang, Hongzhi; Das, Sandhitsu R.; Mancuso, Lauren; Kliot, Dasha; Avants, Brian B.; Ding, Song-Lin; Wolk, David A.; Yushkevich, Paul A.

2015-01-01

The entorhinal cortex (ERC) and the perirhinal cortex (PRC) are subregions of the medial temporal lobe (MTL) that play important roles in episodic memory representations, as well as serving as a conduit between other neocortical areas and the hippocampus. They are also the sites where neuronal damage first occurs in Alzheimer’s disease (AD). The ability to automatically quantify the volume and thickness of the ERC and PRC is desirable because these localized measures can potentially serve as better imaging biomarkers for AD and other neurodegenerative diseases. However, large anatomical variation in the PRC makes it a challenging area for analysis. In order to address this problem, we propose an automatic segmentation, clustering, and thickness measurement approach that explicitly accounts for anatomical variation. The approach is targeted to highly anisotropic (0.4×0.4×2.0mm3) T2-weighted MRI scans that are preferred by many authors for detailed imaging of the MTL, but which pose challenges for segmentation and shape analysis. After automatically labeling MTL substructures using multi-atlas segmentation, our method clusters subjects into groups based on the shape of the PRC, constructs unbiased population templates for each group, and uses the smooth surface representations obtained during template construction to extract regional thickness measurements in the space of each subject. The proposed thickness measures are evaluated in the context of discrimination between patients with Mild Cognitive Impairment (MCI) and normal controls (NC). PMID:25320785

The anatomic basis of lingual nerve trauma associated with inferior alveolar block injections.

PubMed

Morris, Christopher D; Rasmussen, Jared; Throckmorton, Gaylord S; Finn, Richard

2010-11-01

This study describes the anatomic variability in the position of the lingual nerve in the pterygomandibular space, the location of the inferior alveolar nerve block injection. Simulated standard landmark-based inferior alveolar nerve blocks were administered to 44 fixed sagitally bisected cadaver heads. Measurements were made of the diameter of the nerves and distances between the needle and selected anatomic landmarks and the nerves. Of 44 simulated injections, 42 (95.5%) passed lateral to the lingual nerve, 7 (16%) passed within 0.1 mm of the nerve, and 2 (4.5%) penetrated the nerve. The position of the lingual nerve relative to bony landmarks within the interpterygoid fascia was highly variable. Variation in the position of the lingual nerve is an important contributor to lingual nerve trauma during inferior alveolar block injections. This factor should be an important part of preoperative informed consent. Copyright © 2010 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

The prepatellar bursa: cadaveric investigation of regional anatomy with MRI after sonographically guided bursography.

PubMed

Aguiar, Rodrigo O; Viegas, Flavio C; Fernandez, Rodrigo Y; Trudell, Debra; Haghighi, Parviz; Resnick, Donald

2007-04-01

The purpose of this study was to use MRI and anatomic correlation in cadavers to show the macroscopic anatomic configuration of the prepatellar bursa. MRI of the prepatellar bursa of nine cadaveric knees was performed after sonographically guided bursography. The images were compared with those seen on anatomic sectioning. Histologic analysis was obtained in two specimens. Mean dimensions of the prepatellar bursa in the craniocaudal, lateromedial, and anteroposterior planes were 39.7, 40.5, and 3.2 mm, respectively. A trilaminar aspect of the bursa was shown in seven of the nine knees (78%) and a bilaminar appearance in two of the nine knees (22%). Lateral extension of the bursa over the patella was observed in three knees (33%) and medial extension in one knee (11%). On histopathologic analysis, three potential bursal spaces were found. The prepatellar bursa is most commonly a trilaminar structure, and variation in its relation to the patella can occur.

The facial nerve: anatomy and associated disorders for oral health professionals.

PubMed

Takezawa, Kojiro; Townsend, Grant; Ghabriel, Mounir

2018-04-01

The facial nerve, the seventh cranial nerve, is of great clinical significance to oral health professionals. Most published literature either addresses the central connections of the nerve or its peripheral distribution but few integrate both of these components and also highlight the main disorders affecting the nerve that have clinical implications in dentistry. The aim of the current study is to provide a comprehensive description of the facial nerve. Multiple aspects of the facial nerve are discussed and integrated, including its neuroanatomy, functional anatomy, gross anatomy, clinical problems that may involve the nerve, and the use of detailed anatomical knowledge in the diagnosis of the site of facial nerve lesion in clinical neurology. Examples are provided of disorders that can affect the facial nerve during its intra-cranial, intra-temporal and extra-cranial pathways, and key aspects of clinical management are discussed. The current study is complemented by original detailed dissections and sketches that highlight key anatomical features and emphasise the extent and nature of anatomical variations displayed by the facial nerve.

Arthroscopic approach and anatomy of the hip

PubMed Central

Aprato, Alessandro; Giachino, Matteo; Masse, Alessandro

2016-01-01

Summary Background Hip arthroscopy has gained popularity among the orthopedic community and a precise assessment of indications, techniques and results is constantly brought on. Methods In this chapter the principal standard entry portals for central and peripheral compartment are discussed. The description starts from the superficial landmarks for portals placement and continues with the deep layers. For each entry point an illustration of the main structures encountered is provided and the principal structures at risk for different portals are accurately examined. Articular anatomical description is carried out from the arthroscope point of view and sub-divided into central and peripheral compartment. The two compartments are systematically analyzed and the accessible articular areas for each portal explained. Moreover, some anatomical variations that can be found in the normal hip are reported. Conclusion The anatomical knowledge of the hip joint along with a precise notion of the structures encountered with the arthroscope is an essential requirement for a secure and successful surgery. Level of evidence: V. PMID:28066735

Length and Geometric Patterns of the Greater Palatine Canal Observed in Cone Beam Computed Tomography

PubMed Central

Howard-Swirzinski, Karen; Edwards, Paul C.; Saini, Tarnjit S.; Norton, Neil S.

2010-01-01

The greater palatine canal is an important anatomical structure that is often utilized as a pathway for infiltration of local anesthesia to affect sensation and hemostasis. Increased awareness of the length and anatomic variation in the anatomy of this structure is important when performing surgical procedures in this area (e.g., placement of osseointegrated dental implants). We examined the anatomy of the greater palatine canal using data obtained from CBCT scans of 500 subjects. Both right and left canals were viewed (N = 1000) in coronal and sagittal planes, and their paths and lengths determined. The average length of the greater palatine canal was 29 mm (±3 mm), with a range from 22 to 40 mm. Coronally, the most common anatomic pattern consisted of the canal traveling inferior-laterally for a distance then directly inferior for the remainder (43.3%). In the sagittal view, the canal traveled most frequently at an anterior-inferior angle (92.9%). PMID:20871845

SU-F-J-180: A Reference Data Set for Testing Two Dimension Registration Algorithms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dankwa, A; Castillo, E; Guerrero, T

Purpose: To create and characterize a reference data set for testing image registration algorithms that transform portal image (PI) to digitally reconstructed radiograph (DRR). Methods: Anterior-posterior (AP) and Lateral (LAT) projection and DRR image pairs from nine cases representing four different anatomical sites (head and neck, thoracic, abdominal, and pelvis) were selected for this study. Five experts will perform manual registration by placing landmarks points (LMPs) on the DRR and finding their corresponding points on the PI using computer assisted manual point selection tool (CAMPST), a custom-made MATLAB software tool developed in house. The landmark selection process will be repeatedmore » on both the PI and the DRR in order to characterize inter- and -intra observer variations associated with the point selection process. Inter and an intra observer variation in LMPs was done using Bland-Altman (B&A) analysis and one-way analysis of variance. We set our limit such that the absolute value of the mean difference between the readings should not exceed 3mm. Later on in this project we will test different two dimension (2D) image registration algorithms and quantify the uncertainty associated with their registration. Results: Using one-way analysis of variance (ANOVA) there was no variations within the readers. When Bland-Altman analysis was used the variation within the readers was acceptable. The variation was higher in the PI compared to the DRR.ConclusionThe variation seen for the PI is because although the PI has a much better spatial resolution the poor resolution on the DRR makes it difficult to locate the actual corresponding anatomical feature on the PI. We hope this becomes more evident when all the readers complete the point selection. The reason for quantifying inter- and -intra observer variation tells us to what degree of accuracy a manual registration can be done. Research supported by William Beaumont Hospital Research Start Up Fund.« less

Performance evaluation of image denoising developed using convolutional denoising autoencoders in chest radiography

NASA Astrophysics Data System (ADS)

Lee, Donghoon; Choi, Sunghoon; Kim, Hee-Joung

2018-03-01

When processing medical images, image denoising is an important pre-processing step. Various image denoising algorithms have been developed in the past few decades. Recently, image denoising using the deep learning method has shown excellent performance compared to conventional image denoising algorithms. In this study, we introduce an image denoising technique based on a convolutional denoising autoencoder (CDAE) and evaluate clinical applications by comparing existing image denoising algorithms. We train the proposed CDAE model using 3000 chest radiograms training data. To evaluate the performance of the developed CDAE model, we compare it with conventional denoising algorithms including median filter, total variation (TV) minimization, and non-local mean (NLM) algorithms. Furthermore, to verify the clinical effectiveness of the developed denoising model with CDAE, we investigate the performance of the developed denoising algorithm on chest radiograms acquired from real patients. The results demonstrate that the proposed denoising algorithm developed using CDAE achieves a superior noise-reduction effect in chest radiograms compared to TV minimization and NLM algorithms, which are state-of-the-art algorithms for image noise reduction. For example, the peak signal-to-noise ratio and structure similarity index measure of CDAE were at least 10% higher compared to conventional denoising algorithms. In conclusion, the image denoising algorithm developed using CDAE effectively eliminated noise without loss of information on anatomical structures in chest radiograms. It is expected that the proposed denoising algorithm developed using CDAE will be effective for medical images with microscopic anatomical structures, such as terminal bronchioles.

Optimizing the Use of Cadavers by Integrating Pathology during Anatomy Dissection

ERIC Educational Resources Information Center

Geldenhuys, Elsje-Márie; Burger, Elsie Helena; van Helden, Paul David; Mole, Calvin Gerald; Kotzé, Sanet Henriët

2016-01-01

An accurate knowledge of anatomy, especially natural variation within individuals, is of vital clinical importance. Cadaver dissection during anatomical training may be a valuable introduction to pathology for undergraduate students, which can contribute greatly to a successful medical career. The purpose of this study was to determine the extent…

Imaging of the coronary sinus: normal anatomy and congenital abnormalities.

PubMed

Shah, Sanket S; Teague, Shawn D; Lu, Jimmy C; Dorfman, Adam L; Kazerooni, Ella A; Agarwal, Prachi P

2012-01-01

Knowledge of the anatomy of the coronary sinus (CS) and cardiac venous drainage is important because of its relevance in electrophysiologic procedures and cardiac surgeries. Several procedures make use of the CS, such as left ventricular pacing, mapping and ablation of arrhythmias, retrograde cardioplegia, targeted drug delivery, and stem cell therapy. As a result, it is more important for physicians interpreting the results of computed tomographic (CT) examinations dedicated to the heart or including the heart to be able to identify normal variants and congenital anomalies and to understand their clinical importance. Abnormalities of the CS range from anatomic morphologic variations to hemodynamically significant anomalies such as an unroofed CS, anomalous pulmonary venous connection to the CS, and coronary artery-CS fistula. It can be important to identify some anatomic variations, even though they are clinically occult, to ensure appropriate preprocedural planning. Both CT and magnetic resonance imaging provide excellent noninvasive depiction of the anatomy and anomalies of the CS. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.324105220/-/DC1.

Extensive basal ganglia edema caused by a traumatic carotid-cavernous fistula: a rare presentation related to a basal vein of Rosenthal anatomical variation.

PubMed

Ract, Isabelle; Drier, Aurélie; Leclercq, Delphine; Sourour, Nader; Gabrieli, Joseph; Yger, Marion; Nouet, Aurélien; Dormont, Didier; Chiras, Jacques; Clarençon, Frédéric

2014-07-01

The authors report a very rare presentation of traumatic carotid-cavernous fistula (CCF) with extensive edema of the basal ganglia and brainstem because of an anatomical variation of the basal vein of Rosenthal (BVR). A 45-year-old woman was admitted to the authors' institution for left hemiparesis, dysarthria, and a comatose state caused by right orbital trauma from a thin metal rod. Brain MRI showed a right CCF and vasogenic edema of the right side of the brainstem, right temporal lobe, and basal ganglia. Digital subtraction angiography confirmed a high-flow direct CCF and revealed a hypoplastic second segment of the BVR responsible for the hypertension in inferior striate veins and venous congestion. Endovascular treatment was performed on an emergency basis. One month after treatment, the patient's symptoms and MRI signal abnormalities almost totally disappeared. Basal ganglia and brainstem venous congestion may occur in traumatic CCF in cases of a hypoplastic or agenetic second segment of the BVR and may provoke emergency treatment.

Unification of multi-species vertebrate anatomy ontologies for comparative biology in Uberon

PubMed Central

2014-01-01

Background Elucidating disease and developmental dysfunction requires understanding variation in phenotype. Single-species model organism anatomy ontologies (ssAOs) have been established to represent this variation. Multi-species anatomy ontologies (msAOs; vertebrate skeletal, vertebrate homologous, teleost, amphibian AOs) have been developed to represent ‘natural’ phenotypic variation across species. Our aim has been to integrate ssAOs and msAOs for various purposes, including establishing links between phenotypic variation and candidate genes. Results Previously, msAOs contained a mixture of unique and overlapping content. This hampered integration and coordination due to the need to maintain cross-references or inter-ontology equivalence axioms to the ssAOs, or to perform large-scale obsolescence and modular import. Here we present the unification of anatomy ontologies into Uberon, a single ontology resource that enables interoperability among disparate data and research groups. As a consequence, independent development of TAO, VSAO, AAO, and vHOG has been discontinued. Conclusions The newly broadened Uberon ontology is a unified cross-taxon resource for metazoans (animals) that has been substantially expanded to include a broad diversity of vertebrate anatomical structures, permitting reasoning across anatomical variation in extinct and extant taxa. Uberon is a core resource that supports single- and cross-species queries for candidate genes using annotations for phenotypes from the systematics, biodiversity, medical, and model organism communities, while also providing entities for logical definitions in the Cell and Gene Ontologies. The ontology release files associated with the ontology merge described in this manuscript are available at: http://purl.obolibrary.org/obo/uberon/releases/2013-02-21/ Current ontology release files are available always available at: http://purl.obolibrary.org/obo/uberon/releases/ PMID:25009735

Anatomical and morphological spine variation in Gymnocalycium kieslingii subsp. castaneum (Cactaceae).

PubMed

Gebauer, Roman; Řepka, Radomír; Šmudla, Radek; Mamoňová, Miroslava; Ďurkovič, Jaroslav

2016-01-01

Although spine variation within cacti species or populations is assumed to be large, the minimum sample size of different spine anatomical and morphological traits required for species description is less studied. There are studies where only 2 spines were used for taxonomical comparison amnog species. Therefore, the spine structure variation within areoles and individuals of one population of Gymnocalycium kieslingii subsp. castaneum (Ferrari) Slaba was analyzed. Fifteen plants were selected and from each plant one areole from the basal, middle and upper part of the plant body was sampled. A scanning electron microscopy was used for spine surface description and a light microscopy for measurements of spine width, thickness, cross-section area, fiber diameter and fiber cell wall thickness. The spine surface was more visible and damaged less in the upper part of the plant body than in the basal part. Large spine and fiber differences were found between upper and lower parts of the plant body, but also within single areoles. In general, the examined traits in the upper part had by 8-17% higher values than in the lower parts. The variation of spine and fiber traits within areoles was lower than the differences between individuals. The minimum sample size was largely influenced by the studied spine and fiber traits, ranging from 1 to 70 spines. The results provide pioneer information useful in spine sample collection in the field for taxonomical, biomechanical and structural studies. Nevertheless, similar studies should be carried out for other cacti species to make generalizations. The large spine and fiber variation within areoles observed in our study indicates a very complex spine morphogenesis.

Anatomical and morphological spine variation in Gymnocalycium kieslingii subsp. castaneum (Cactaceae)

PubMed Central

Gebauer, Roman; Řepka, Radomír; Šmudla, Radek; Mamoňová, Miroslava; Ďurkovič, Jaroslav

2016-01-01

Abstract Although spine variation within cacti species or populations is assumed to be large, the minimum sample size of different spine anatomical and morphological traits required for species description is less studied. There are studies where only 2 spines were used for taxonomical comparison amnog species. Therefore, the spine structure variation within areoles and individuals of one population of Gymnocalycium kieslingii subsp. castaneum (Ferrari) Slaba was analyzed. Fifteen plants were selected and from each plant one areole from the basal, middle and upper part of the plant body was sampled. A scanning electron microscopy was used for spine surface description and a light microscopy for measurements of spine width, thickness, cross-section area, fiber diameter and fiber cell wall thickness. The spine surface was more visible and damaged less in the upper part of the plant body than in the basal part. Large spine and fiber differences were found between upper and lower parts of the plant body, but also within single areoles. In general, the examined traits in the upper part had by 8–17% higher values than in the lower parts. The variation of spine and fiber traits within areoles was lower than the differences between individuals. The minimum sample size was largely influenced by the studied spine and fiber traits, ranging from 1 to 70 spines. The results provide pioneer information useful in spine sample collection in the field for taxonomical, biomechanical and structural studies. Nevertheless, similar studies should be carried out for other cacti species to make generalizations. The large spine and fiber variation within areoles observed in our study indicates a very complex spine morphogenesis. PMID:27698579

Modeling patterns of anatomical deformations in prostate patients undergoing radiation therapy with an endorectal balloon

NASA Astrophysics Data System (ADS)

Brion, Eliott; Richter, Christian; Macq, Benoit; Stützer, Kristin; Exner, Florian; Troost, Esther; Hölscher, Tobias; Bondar, Luiza

2017-03-01

External beam radiation therapy (EBRT) treats cancer by delivering daily fractions of radiation to a target volume. For prostate cancer, the target undergoes day-to-day variations in position, volume, and shape. For stereotactic photon and for proton EBRT, endorectal balloons (ERBs) can be used to limit variations. To date, patterns of non-rigid variations for patients with ERB have not been modeled. We extracted and modeled the patient-specific patterns of variations, using regularly acquired CT-images, non-rigid point cloud registration, and principal component analysis (PCA). For each patient, a non-rigid point-set registration method, called Coherent Point Drift, (CPD) was used to automatically generate landmark correspondences between all target shapes. To ensure accurate registrations, we tested and validated CPD by identifying parameter values leading to the smallest registration errors (surface matching error 0.13+/-0.09 mm). PCA demonstrated that 88+/-3.2% of the target motion could be explained using only 4 principal modes. The most dominant component of target motion is a squeezing and stretching in the anterior-posterior and superior-inferior directions. A PCA model of daily landmark displacements, generated using 6 to 10 CT-scans, could explain well the target motion for the CT-scans not included in the model (modeling error decreased from 1.83+/-0.8 mm for 6 CT-scans to 1.6+/-0.7 mm for 10 CT-scans). PCA modeling error was smaller than the naive approximation by the mean shape (approximation error 2.66+/-0.59 mm). Future work will investigate the use of the PCA-model to improve the accuracy of EBRT techniques that are highly susceptible to anatomical variations such as, proton therapy

Carotid artery protrusion and dehiscence in patients with acromegaly.

PubMed

Sasagawa, Yasuo; Tachibana, Osamu; Doai, Mariko; Hayashi, Yasuhiko; Tonami, Hisao; Iizuka, Hideaki; Nakada, Mitsutoshi

2016-10-01

Acromegaly is a systemic disease which causes multiple bony alterations. Some authors reported that acromegalic patients have risk factors for an intraoperative vascular injury due to the specific anatomical features of their sphenoid sinus. The objective of our study was to analyze the anatomic characteristics of sphenoid sinus in acromegalic patients compared with controls, by evaluation of computed tomography (CT) findings. We examined 45 acromegalic (acromegaly group) and 45 non-acromegalic patients (control group) with pituitary adenomas who were matched for sex, age, height, tumor size, and cavernous sinus invasion (Knosp grade). Preoperative CT of the pituitary region including the sphenoid sinus was used to evaluate the following anatomic characteristics: type of sphenoid sinus (sellar or pre-sellar/conchal); intrasphenoid septa (non/single or multiple); carotid artery protrusion; carotid artery dehiscence; intercarotid distance. Sixteen acromegalic patients (35.5 %) and 6 controls (13.3 %) had carotid artery protrusion. Additionally, 10 acromegalic patients (22.2 %) and 3 controls (6.6 %) had carotid artery dehiscence. Carotid artery protrusion and dehiscence were more frequent in the acromegaly group than in control group (p = 0.013 and 0.035, respectively). Other anatomic characteristics (type of sphenoid sinus, intrasphenoid septa, and intracarotid distance) showed no significant differences between acromegaly and control groups. Our study suggests that carotid artery protrusion and dehiscence occur more frequently among acromegalic patients, compared with non-acromegalic patients. It is important for surgeons to be aware of these anatomic variations to avoid vital complications, such as carotid injuries, during surgery.

Relevant Feature Set Estimation with a Knock-out Strategy and Random Forests

PubMed Central

Ganz, Melanie; Greve, Douglas N.; Fischl, Bruce; Konukoglu, Ender

2015-01-01

Group analysis of neuroimaging data is a vital tool for identifying anatomical and functional variations related to diseases as well as normal biological processes. The analyses are often performed on a large number of highly correlated measurements using a relatively smaller number of samples. Despite the correlation structure, the most widely used approach is to analyze the data using univariate methods followed by post-hoc corrections that try to account for the data’s multivariate nature. Although widely used, this approach may fail to recover from the adverse effects of the initial analysis when local effects are not strong. Multivariate pattern analysis (MVPA) is a powerful alternative to the univariate approach for identifying relevant variations. Jointly analyzing all the measures, MVPA techniques can detect global effects even when individual local effects are too weak to detect with univariate analysis. Current approaches are successful in identifying variations that yield highly predictive and compact models. However, they suffer from lessened sensitivity and instabilities in identification of relevant variations. Furthermore, current methods’ user-defined parameters are often unintuitive and difficult to determine. In this article, we propose a novel MVPA method for group analysis of high-dimensional data that overcomes the drawbacks of the current techniques. Our approach explicitly aims to identify all relevant variations using a “knock-out” strategy and the Random Forest algorithm. In evaluations with synthetic datasets the proposed method achieved substantially higher sensitivity and accuracy than the state-of-the-art MVPA methods, and outperformed the univariate approach when the effect size is low. In experiments with real datasets the proposed method identified regions beyond the univariate approach, while other MVPA methods failed to replicate the univariate results. More importantly, in a reproducibility study with the well-known ADNI dataset the proposed method yielded higher stability and power than the univariate approach. PMID:26272728

Anatomical curve identification

PubMed Central

Bowman, Adrian W.; Katina, Stanislav; Smith, Joanna; Brown, Denise

2015-01-01

Methods for capturing images in three dimensions are now widely available, with stereo-photogrammetry and laser scanning being two common approaches. In anatomical studies, a number of landmarks are usually identified manually from each of these images and these form the basis of subsequent statistical analysis. However, landmarks express only a very small proportion of the information available from the images. Anatomically defined curves have the advantage of providing a much richer expression of shape. This is explored in the context of identifying the boundary of breasts from an image of the female torso and the boundary of the lips from a facial image. The curves of interest are characterised by ridges or valleys. Key issues in estimation are the ability to navigate across the anatomical surface in three-dimensions, the ability to recognise the relevant boundary and the need to assess the evidence for the presence of the surface feature of interest. The first issue is addressed by the use of principal curves, as an extension of principal components, the second by suitable assessment of curvature and the third by change-point detection. P-spline smoothing is used as an integral part of the methods but adaptations are made to the specific anatomical features of interest. After estimation of the boundary curves, the intermediate surfaces of the anatomical feature of interest can be characterised by surface interpolation. This allows shape variation to be explored using standard methods such as principal components. These tools are applied to a collection of images of women where one breast has been reconstructed after mastectomy and where interest lies in shape differences between the reconstructed and unreconstructed breasts. They are also applied to a collection of lip images where possible differences in shape between males and females are of interest. PMID:26041943

Automated anatomical labeling of bronchial branches using multiple classifiers and its application to bronchoscopy guidance based on fusion of virtual and real bronchoscopy

NASA Astrophysics Data System (ADS)

Ota, Shunsuke; Deguchi, Daisuke; Kitasaka, Takayuki; Mori, Kensaku; Suenaga, Yasuhito; Hasegawa, Yoshinori; Imaizumi, Kazuyoshi; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi

2008-03-01

This paper presents a method for automated anatomical labeling of bronchial branches (ALBB) extracted from 3D CT datasets. The proposed method constructs classifiers that output anatomical names of bronchial branches by employing the machine-learning approach. We also present its application to a bronchoscopy guidance system. Since the bronchus has a complex tree structure, bronchoscopists easily tend to get disoriented and lose the way to a target location. A bronchoscopy guidance system is strongly expected to be developed to assist bronchoscopists. In such guidance system, automated presentation of anatomical names is quite useful information for bronchoscopy. Although several methods for automated ALBB were reported, most of them constructed models taking only variations of branching patterns into account and did not consider those of running directions. Since the running directions of bronchial branches differ greatly in individuals, they could not perform ALBB accurately when running directions of bronchial branches were different from those of models. Our method tries to solve such problems by utilizing the machine-learning approach. Actual procedure consists of three steps: (a) extraction of bronchial tree structures from 3D CT datasets, (b) construction of classifiers using the multi-class AdaBoost technique, and (c) automated classification of bronchial branches by using the constructed classifiers. We applied the proposed method to 51 cases of 3D CT datasets. The constructed classifiers were evaluated by leave-one-out scheme. The experimental results showed that the proposed method could assign correct anatomical names to bronchial branches of 89.1% up to segmental lobe branches. Also, we confirmed that it was quite useful to assist the bronchoscopy by presenting anatomical names of bronchial branches on real bronchoscopic views.

Dynamic article: surgical anatomical planes for complete mesocolic excision and applied vascular anatomy of the right colon.

PubMed

Açar, Halil İbrahim; Cömert, Ayhan; Avşar, Abdullah; Çelik, Safa; Kuzu, Mehmet Ayhan

2014-10-01

Lower local recurrence rates and better overall survival are associated with complete mesocolic excision with central vascular ligation for treatment of colon cancer. To accomplish this, surgeons need to pay special attention to the surgical anatomical planes and vascular anatomy of the colon. However, surgical education in this area has been neglected. The aim of this study is to define the correct surgical anatomical planes for complete mesocolic excision with central vascular ligation and to demonstrate the correct dissection technique for protecting anatomical structures. Macroscopic and microscopic surgical dissections were performed on 12 cadavers in the anatomy laboratory and on autopsy specimens. The dissections were recorded as video clips. Dissections were performed in accordance with the complete mesocolic excision technique on 10 male and 2 female cadavers. Vascular structures, autonomic nerves, and related fascias were shown. Within each step of the surgical procedure, important anatomical structures were displayed on still images captured from videos by animations. Three crucial steps for complete mesocolic excision with central vascular ligation are demonstrated on the cadavers: 1) full mobilization of the superior mesenteric root following the embryological planes between the visceral and the parietal fascias; 2) mobilization of the mesocolon from the duodenum and the pancreas and identification of vascular structures, especially the veins around the pancreas; and 3) central vascular ligation of the colonic vessels at their origin, taking into account the vascular variations within the mesocolonic vessels and the autonomic nerves around the superior mesenteric artery. The limitation of this study was the number of the cadavers used. Successful complete mesocolic excision with central vascular ligation depends on an accurate knowledge of the surgical anatomical planes and the vascular anatomy of the colon.

Evolution of wood anatomical characters in Nepenthes and close relatives of Caryophyllales.

PubMed

Schwallier, Rachel; Gravendeel, Barbara; de Boer, Hugo; Nylinder, Stephan; van Heuven, Bertie Joan; Sieder, Anton; Sumail, Sukaibin; van Vugt, Rogier; Lens, Frederic

2017-05-01

Nepenthes attracts wide attention with its spectacularly shaped carnivorous pitchers, cultural value and horticultural curiosity. Despite the plant's iconic fascination, surprisingly little anatomical detail is known about the genus beyond its modified leaf tip traps. Here, the wood anatomical diversity of Nepenthes is explored. This diversity is further assessed with a phylogenetic framework to investigate whether the wood characters within the genus are relevant from an evolutionary or ecological perspective, or rather depend on differences in developmental stages, growth habits, substrates or precipitation. Observations were performed using light microscopy and scanning electron microscopy. Ancestral states of selected wood and pith characters were reconstructed using an existing molecular phylogeny for Nepenthes and a broader Caryophyllales framework. Pairwise comparisons were assessed for possible relationships between wood anatomy and developmental stages, growth habits, substrates and ecology. Wood anatomy of Nepenthes is diffuse porous, with mainly solitary vessels showing simple, bordered perforation plates and alternate intervessel pits, fibres with distinctly bordered pits (occasionally septate), apotracheal axial parenchyma and co-occurring uni- and multiseriate rays often including silica bodies. Precipitation and growth habit (stem length) are linked with vessel density and multiseriate ray height, while soil type correlates with vessel diameter, vessel element length and maximum ray width. For Caryophyllales as a whole, silica grains, successive cambia and bordered perforation plates are the result of convergent evolution. Peculiar helical sculpturing patterns within various cell types occur uniquely within the insectivorous clade of non-core Caryophyllales. The wood anatomical variation in Nepenthes displays variation for some characters dependent on soil type, precipitation and stem length, but is largely conservative. The helical-banded fibre-sclereids that mainly occur idioblastically in pith and cortex are synapomorphic for Nepenthes , while other typical Nepenthes characters evolved convergently in different Caryophyllales lineages. © The Author 2017. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Evolution of wood anatomical characters in Nepenthes and close relatives of Caryophyllales

PubMed Central

Gravendeel, Barbara; de Boer, Hugo; Nylinder, Stephan; van Heuven, Bertie Joan; Sieder, Anton; Sumail, Sukaibin; van Vugt, Rogier; Lens, Frederic

2017-01-01

Abstract Background and Aims Nepenthes attracts wide attention with its spectacularly shaped carnivorous pitchers, cultural value and horticultural curiosity. Despite the plant’s iconic fascination, surprisingly little anatomical detail is known about the genus beyond its modified leaf tip traps. Here, the wood anatomical diversity of Nepenthes is explored. This diversity is further assessed with a phylogenetic framework to investigate whether the wood characters within the genus are relevant from an evolutionary or ecological perspective, or rather depend on differences in developmental stages, growth habits, substrates or precipitation. Methods Observations were performed using light microscopy and scanning electron microscopy. Ancestral states of selected wood and pith characters were reconstructed using an existing molecular phylogeny for Nepenthes and a broader Caryophyllales framework. Pairwise comparisons were assessed for possible relationships between wood anatomy and developmental stages, growth habits, substrates and ecology. Key Results Wood anatomy of Nepenthes is diffuse porous, with mainly solitary vessels showing simple, bordered perforation plates and alternate intervessel pits, fibres with distinctly bordered pits (occasionally septate), apotracheal axial parenchyma and co-occurring uni- and multiseriate rays often including silica bodies. Precipitation and growth habit (stem length) are linked with vessel density and multiseriate ray height, while soil type correlates with vessel diameter, vessel element length and maximum ray width. For Caryophyllales as a whole, silica grains, successive cambia and bordered perforation plates are the result of convergent evolution. Peculiar helical sculpturing patterns within various cell types occur uniquely within the insectivorous clade of non-core Caryophyllales. Conclusions The wood anatomical variation in Nepenthes displays variation for some characters dependent on soil type, precipitation and stem length, but is largely conservative. The helical-banded fibre-sclereids that mainly occur idioblastically in pith and cortex are synapomorphic for Nepenthes, while other typical Nepenthes characters evolved convergently in different Caryophyllales lineages. PMID:28387789

Trade-offs between xylem hydraulic properties, wood anatomy and yield in Populus.

PubMed

Hajek, Peter; Leuschner, Christoph; Hertel, Dietrich; Delzon, Sylvain; Schuldt, Bernhard

2014-07-01

Trees face the dilemma that achieving high plant productivity is accompanied by a risk of drought-induced hydraulic failure due to a trade-off in the trees' vascular system between hydraulic efficiency and safety. By investigating the xylem anatomy of branches and coarse roots, and measuring branch axial hydraulic conductivity and vulnerability to cavitation in 4-year-old field-grown aspen plants of five demes (Populus tremula L. and Populus tremuloides Michx.) differing in growth rate, we tested the hypotheses that (i) demes differ in wood anatomical and hydraulic properties, (ii) hydraulic efficiency and safety are related to xylem anatomical traits, and (iii) aboveground productivity and hydraulic efficiency are negatively correlated to cavitation resistance. Significant deme differences existed in seven of the nine investigated branch-related anatomical and hydraulic traits but only in one of the four coarse-root-related anatomical traits; this likely is a consequence of high intra-plant variation in root morphology and the occurrence of a few 'high-conductivity roots'. Growth rate was positively related to branch hydraulic efficiency (xylem-specific conductivity) but not to cavitation resistance; this indicates that no marked trade-off exists between cavitation resistance and growth. Both branch hydraulic safety and hydraulic efficiency significantly depended on vessel size and were related to the genetic distance between the demes, while the xylem pressure causing 88% loss of hydraulic conductivity (P88 value) was more closely related to hydraulic efficiency than the commonly used P50 value. Deme-specific variation in the pit membrane structure may explain why vessel size was not directly linked to growth rate. We conclude that branch hydraulic efficiency is an important growth-influencing trait in aspen, while the assumed trade-off between productivity and hydraulic safety is weak. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

SU-E-J-111: Finite Element-Based Deformable Image Registration of Pleural Cavity for Photodynamic Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penjweini, R; Zhu, T

Purpose: The pleural volumes will deform during surgery portion of the pleural photodynamic therapy (PDT) of lung cancer when the pleural cavity is opened. This impact the delivered dose when using highly conformal treatment techniques. In this study, a finite element-based (FEM) deformable image registration is used to quantify the anatomical variation between the contours for the pleural cavities obtained in the operating room and those determined from pre-surgery computed tomography (CT) scans. Methods: An infrared camera-based navigation system (NDI) is used during PDT to track the anatomical changes and contour the lung and chest cavity. A series of CTsmore » of the lungs, in the same patient, are also acquired before the surgery. The structure contour of lung and the CTs are processed and contoured in Matlab and MeshLab. Then, the contours are imported into COMSOL Multiphysics 5.0, where the FEM-based deformable image registration is obtained using the deformed mesh - moving mesh (ALE) model. The NDI acquired lung contour is considered as the reference contour, and the CT contour is used as the target one, which will be deformed. Results: The reconstructed three-dimensional contours from both NDI and CT can be converted to COMSOL so that a three-dimensional ALE model can be developed. The contours can be registered using COMSOL ALE moving mesh model, which takes into account the deformation along x, y and z-axes. The deformed contour has good matches to the reference contour after the dynamic matching process. The resulting 3D deformation map can be used to obtain the locations of other critical anatomic structures, e.g., heart, during surgery. Conclusion: Deformable image registration can fuse images acquired by different modalities. It provides insights into the development of phenomenon and variation in normal anatomical structures over time. The initial assessments of three-dimensional registration show good agreement.« less

Estimating abdominal adipose tissue with DXA and anthropometry.

PubMed

Hill, Alison M; LaForgia, Joe; Coates, Alison M; Buckley, Jonathan D; Howe, Peter R C

2007-02-01

To identify an anatomically defined region of interest (ROI) from DXA assessment of body composition that when combined with anthropometry can be used to accurately predict intra-abdominal adipose tissue (IAAT) in overweight/obese individuals. Forty-one postmenopausal women (age, 49 to 66 years; BMI, 26 to 37 kg/m(2)) underwent anthropometric and body composition assessments. ROI were defined as quadrilateral boxes extending 5 or 10 cm above the iliac crest and laterally to the edges of the abdominal soft tissue. A single-slice computed tomography (CT) scan was measured at the L3 to L4 intervertebral space, and abdominal skinfolds were taken. Forward step-wise regression revealed the best predictor model of IAAT area measured by CT (r(2) = 0.68, standard error of estimate = 17%) to be: IAAT area (centimeters squared) = 51.844 + DXA 10-cm ROI (grams) (0.031) + abdominal skinfold (millimeters) (1.342). Interobserver reliability for fat mass (r = 0.994; coefficient of variation, 2.60%) and lean mass (r = 0.986, coefficient of variation, 2.67%) in the DXA 10-cm ROI was excellent. This study has identified a DXA ROI that can be reliably measured using prominent anatomical landmarks, in this case, the iliac crest. Using this ROI, combined with an abdominal skinfold measurement, we have derived an equation to predict IAAT in overweight/obese postmenopausal women. This approach offers a simpler, safer, and more cost-effective method than CT for assessing the efficacy of lifestyle interventions aimed at reducing IAAT. However, this warrants further investigation and validation with an independent cohort.

New Strategies in Radiation Therapy: Exploiting the Full Potential of Protons

PubMed Central

Mohan, Radhe; Mahajan, Anita; Minsky, Bruce D.

2013-01-01

Protons provide significant dosimetric advantages compared with photons due to their unique depth-dose distribution characteristics. However, they are more sensitive to the effects of intra- and inter-treatment fraction anatomic variations and uncertainties in treatment setup. Furthermore, in the current practice of proton therapy, the biological effectiveness of protons relative to photons is assumed to have a generic fixed value of 1.1. However, this is a simplification, and it is likely higher in different portions of the proton beam. Current clinical practice and trials have not fully exploited the unique physical and biological properties of protons. Intensity-modulated proton therapy, with its ability to manipulate energies (in addition to intensities), provides an entirely new dimension, which, with ongoing research, has considerable potential to increase the therapeutic ratio. PMID:24077353

New strategies in radiation therapy: exploiting the full potential of protons.

PubMed

Mohan, Radhe; Mahajan, Anita; Minsky, Bruce D

2013-12-01

Protons provide significant dosimetric advantages compared with photons because of their unique depth-dose distribution characteristics. However, they are more sensitive to the effects of intra- and intertreatment fraction anatomic variations and uncertainties in treatment setup. Furthermore, in the current practice of proton therapy, the biologic effectiveness of protons relative to photons is assumed to have a generic fixed value of 1.1. However, this is a simplification, and it is likely higher in different portions of the proton beam. Current clinical practice and trials have not fully exploited the unique physical and biologic properties of protons. Intensity-modulated proton therapy, with its ability to manipulate energies (in addition to intensities), provides an entirely new dimension, which, with ongoing research, has considerable potential to increase the therapeutic ratio. ©2013 AACR.

Thickened cranial vault and parasagittal keeling: correlated traits and autapomorphies of Homo erectus?

PubMed

Balzeau, Antoine

2013-06-01

Homo erectus sensu lato (s.l.) is a key species in the hominin fossil record for the study of human evolution, being one of the first species discovered and perhaps the most documented, but also because of its long temporal range and having dispersed out of Africa earlier than any other human species. Here I test two proposed autapomorphic traits of H. erectus, namely the increased thickness of the upper cranial vault and parasagittal keeling. The definition of these two anatomical features and their expression and variation among hominids are discussed. The results of this study indicate that the upper vault in Asian H. erectus is not absolutely thicker compared with fossil anatomically modern Homo sapiens, whereas Broken Hill and Petralona have values above the range of variation of H. erectus. Moreover, this anatomical region in Asian H. erectus is not significantly thicker compared with Pan paniscus. In addition, these results demonstrate that cranial vault thickness should not be used to make hypotheses regarding sexual attribution of fossil hominin specimens. I also show that the relation between relief on the external surface of the upper vault, parasagittal keeling and bregmatic eminence, and bone thickness is complex. In this context, the autapomorphic status of the two analysed traits in H. erectus may be rejected. Nevertheless, different patterns in the distribution of bone thickness on the upper vault were identified. Some individual variations are visible, but specificities are observable in samples of different species. The pattern of bone thickness distribution observed in Asian H. erectus, P. paniscus, possibly australopiths, and early Homo or Homo ergaster/erectus appears to be shared by these different species and would be a plesiomorphic trait among hominids. In contrast, two apomorphic states for this feature were identified for Neandertals and H. sapiens. Copyright © 2013 Elsevier Ltd. All rights reserved.

Variability amongst radiographers in the categorization of clinical acceptability for digital trauma radiography

NASA Astrophysics Data System (ADS)

Decoster, Robin; Toomey, Rachel; Smits, Dirk; Mol, Harrie; Verhelle, Filip; Butler, Marie-Louise

2016-03-01

Introduction: Radiographers evaluate anatomical structures to judge clinical acceptability of a radiograph. Whether a radiograph is deemed acceptable for diagnosis or not depends on the individual decision of the radiographer. Individual decisions cause variation in the accepted image quality. To minimise these variations definitions of acceptability, such as in RadLex, were developed. On which criteria radiographers attribute a RadLex categories to radiographs is unknown. Insight into these criteria helps to further optimise definitions and reduce variability in acceptance between radiographers. Therefore, this work aims the evaluation of the correlation between the RadLex classification and the evaluation of anatomical structures, using a Visual Grading Analysis (VGA) Methods: Four radiographers evaluated the visibility of five anatomical structures of 25 lateral cervical spine radiographs on a secondary class display with a VGA. They judged clinical acceptability of each radiograph using RadLex. Relations between VGAS and RadLex category were analysed with Kendall's Tau correlation and Nagelkerke pseudo-R². Results: The overall VGA score (VGAS) and the RadLex score correlate (rτ= 0.62, p<0.01, R2=0.72) strongly. The observers' evaluation of contrast between bone, air (trachea) and soft tissue has low value in predicting (rτ=0.55, p<0.01, R2=0.03) the RadLex score. The reproduction of spinous processes (rτ=0.67, p<0.01, R2=0.31) and the evaluation of the exposure (rτ=0.65, p<0.01, R2=0.56) have a strong correlation with high predictive value for the RadLex score. Conclusion: RadLex scores and VGAS correlate positively, strongly and significantly. The predictive value of bony structures may support the use of these in the judgement of clinical acceptability. Considerable inter-observer variations in the VGAS within a certain RadLex category, suggest that observers use of observer specific cut-off values.

SU-F-I-50: Finite Element-Based Deformable Image Registration of Lung and Heart

DOE Office of Scientific and Technical Information (OSTI.GOV)

Penjweini, R; Kim, M; Zhu, T

Purpose: Photodynamic therapy (PDT) is used after surgical resection to treat the microscopic disease for malignant pleural mesothelioma and to increase survival rates. Although accurate light delivery is imperative to PDT efficacy, the deformation of the pleural volume during the surgery impacts the delivered light dose. To facilitate treatment planning, we use a finite-element-based (FEM) deformable image registration to quantify the anatomical variation of lung and heart volumes between CT pre-(or post-) surgery and surface contours obtained during PDT using an infrared camera-based navigation system (NDI). Methods: NDI is used during PDT to obtain the information of the cumulative lightmore » fluence on every cavity surface point that is being treated. A wand, comprised of a modified endotrachial tube filled with Intralipid and an optical fiber inside the tube, is used to deliver the light during PDT. The position of the treatment is tracked using an attachment with nine reflective passive markers that are seen by the NDI system. Then, the position points are plotted as three-dimensional volume of the pleural cavity using Matlab and Meshlab. A series of computed tomography (CT) scans of the lungs and heart, in the same patient, are also acquired before and after the surgery. The NDI and CT contours are imported into COMSOL Multiphysics, where the FEM-based deformable image registration is obtained. The NDI and CT contours acquired during and post-PDT are considered as the reference, and the Pre-PDT CT contours are used as the target, which will be deformed. Results: Anatomical variation of the lung and heart volumes, taken at different times from different imaging devices, was determined by using our model. The resulting three-dimensional deformation map along x, y and z-axes was obtained. Conclusion: Our model fuses images acquired by different modalities and provides insights into the variation in anatomical structures over time.« less

Lower Lateral Cartilage Cephalic Malposition: An Over-Diagnosed Entity.

PubMed

Hafezi, Farhad; Naghibzadeh, Bijan; Kazemi Ashtiani, Abbas

2018-06-01

Lower lateral cartilage malposition is represented by anterior convexity of the lower lateral cartilage (LLC) dome with posterior pinch, as defined by Sheen and Constantian. This anatomic variation consists of cephalic, or upward and inward, rotation of lateral crura, particularly in bulbous tip patients. In most cases, "bulbous pinch" LLC is positioned toward the medial canthus, not laterally, so it is referred to as cephalic displacement. Accordingly, it is recommended to caudally displace cartilage in the majority of rhinoplasty cases in which variation is seen. The purpose of this paper is to measure the exact angle of lateral crura with fixed reference points on the face. We drew and marked LLC contours and vertical/horizontal lines in 40 consecutive rhinoplasty cases. We then divided them into two groups: (1) bulbous pinch and (2) flat LLCs. The right- and left-sided LLC angles to midline and horizontal lines were measured and compared to assess whether there was any significant difference between the two subgroups. There was no significant difference between the angles of LLC rotation in the bulbous and flat LLCs groups, measured both vertically and horizontally. Based on our findings, although cephalic malposition of LLCs may be present in some patients but in the majority of cases the etiology of nasal lateral wall pinching is not cephalic displacement of lateral crura but most probably is due, rather, to severe convexity of the posterior and lateral crura. According to our findings, cephalic malposition is an uncommon anatomic variation of LLCs that has been reported at high frequency (60-70% of their rhinoplasty cases). This finding may help to correct this deformity into a normal anatomic configuration. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Using ring width correlations to study the effects of plantation density on wood density and anatomical properties of red pine (Pinus resinosa Ait.)

Treesearch

J. Y. Zhu; C. T. Scott; K. L. Scallon; G. C. Myers

2006-01-01

This study demonstrated that average ring width (or average annual radial growth rate) is a reliable parameter to quantify the effects of tree plantation ndensity (growth suppression) on wood density and tracheid anatomical properties. The average ring width successfully correlated wood density and tracheid anatomical properties of red pines (Pinus resinosa Ait.) from...

Endoscopic colloid cyst excision: surgical techniques and nuances.

PubMed

Azab, Waleed Abdelfattah; Najibullah, Mustafa; Yosef, Waleed

2017-06-01

Endoscopic excision of colloid cysts is currently well established as a minimally invasive and highly effective technique that is associated with less morbidity in comparison to microsurgical resection. Operative charts and videos of patients undergoing endoscopic colloid cyst excision were retrieved from the senior author's database of endoscopic procedures and reviewed. This revealed nine trans-foraminal and three trans-septal procedures. Description of the surgical techniques was then formulated. Variation of the technique is based on the specific patho-anatomical features of the colloid cyst being resected. For the trans-foraminal approach, we think that the rotational technique is associated with a more complete removal of the cyst wall and consequently lower recurrence rate.

Novel anatomic variation: heptafurcation of the celiac trunk.

PubMed

Rusu, M C; Manta, B A

2018-04-01

We report here anatomic variants which were found during a retrospective study of a male patient, 54 years old, evaluated in computed tomography: heptafurcation of the celiac trunk (CT) and bilateral double renal arteries. The seven branches of the heptafurcated CT were the (1) left and (2) right inferior phrenic arteries, the (3) splenic and (4) left gastric artery, the (5) common hepatic artery, further sending off the (a) proper, continued as left, hepatic artery and (b) the gastroduodenal artery, (6) a replaced right hepatic artery and (7) the dorsal pancreatic artery. To our knowledge, heptafurcation of the CT was not reported previously. The arterial variants have great importance during various surgical and interventional procedures and should be documented prior to respective procedures.

Modern morphometry: new perspectives in physical anthropology.

PubMed

Mantini, Simone; Ripani, Maurizio

2009-06-01

In the past one hundred years physical anthropology has recourse to more and more efficient methods, which provide several new information regarding, human evolution and biology. Apart from the molecular approach, the introduction of new computed assisted techniques gave rise to a new concept of morphometry. Computed tomography and 3D-imaging, allowed providing anatomical description of the external and inner structures exceeding the problems encountered with the traditional morphometric methods. Furthermore, the support of geometric morphometrics, allowed creating geometric models to investigate morphological variation in terms of evolution, ontogeny and variability. The integration of these new tools gave rise to the virtual anthropology and to a new image of the anthropologist in which anatomical, biological, mathematical statistical and data processing information are fused in a multidisciplinary approach.

Anatomy of the right liver lobe: a surgical analysis in 124 consecutive living donors.

PubMed

Bageacu, S; Abdelaal, A; Ficarelli, S; Elmeteini, M; Boillot, O

2011-01-01

Understanding anatomic variations of the right lobe is fundamental in adult to adult living donor liver transplantation. We analysed anatomy in 124 right liver (RL) donors. Portal vein: normal anatomy was found in 85.5% donors. In 14.5% the main right portal vein (PV) was absent. Hepatic artery: single arterial inflow of the RL was identified in 96% of donors. In 4% two arterial stumps were found. Bile duct: classic anatomy was identified in 50.8% of donors; 9.7% had a trifurcation of the common bile duct; in 7.2% the right anterior and in 15.3% the right posterior bile duct opened into the left bile duct; one segmental bile duct opened directly into the common bile duct in 12.1% and two segmental bile ducts in 4.8%. Hepatic veins (HV): in 74.3% the right HV was the single outflow; in 24.2% significant accessory HV (>5 mm) were preserved, in 2.4% the middle HV was harvested. We found that patients with PV variations had high incidence of multiple bile ducts (88.9%) while patients with single right PV had lower incidence (42.4%) (p = 0.00026). While anatomic variations in the RL donor were common, no contraindication to RL harvesting was noted in this study. © 2011 John Wiley & Sons A/S.

Architecture and functional ecology of the human gastrocnemius muscle-tendon unit.

PubMed

Butler, Erin E; Dominy, Nathaniel J

2016-04-01

The gastrocnemius muscle-tendon unit (MTU) is central to human locomotion. Structural variation in the human gastrocnemius MTU is predicted to affect the efficiency of locomotion, a concept most often explored in the context of performance activities. For example, stiffness of the Achilles tendon varies among individuals with different histories of competitive running. Such a finding highlights the functional variation of individuals and raises the possibility of similar variation between populations, perhaps in response to specific ecological or environmental demands. Researchers often assume minimal variation in human populations, or that industrialized populations represent the human species as well as any other. Yet rainforest hunter-gatherers, which often express the human pygmy phenotype, contradict such assumptions. Indeed, the human pygmy phenotype is a potential model system for exploring the range of ecomorphological variation in the architecture of human hindlimb muscles, a concept we review here. © 2015 Anatomical Society.

The cerebral arterial circle (circulus arteriosus cerebri): an anatomical study in fetus and infant samples.

PubMed

Ardakani, Shahab Kamali; Dadmehr, Majid; Nejat, Farideh; Ansari, Saeed; Eftekhar, Behzad; Tajik, Parvin; El Khashab, Mostafa; Yazdani, Shahrooz; Ghodsi, Mohammad; Mahjoub, Fatemeh; Monajemzadeh, Maryam; Nazparvar, Bashir; Abdi-Rad, Afshin

2008-01-01

Many studies have investigated the variations in the anatomy of each segment of the cerebral arterial circle while a few have addressed the variations of the cerebral arterial circle as a whole. Thirty brains of recently deceased Iranian infants and fetuses were dissected. The dissection process was filmed and digitized so as to be readily available for further studies. The variations of the circle as a whole and segmental variations were evaluated. Variants with uni- and bilateral hypoplasia of posterior communicating arteries (PcoAs) were the most common in our study, similar to previous works. No aplasia of the precommunicating part of the anterior cerebral artery (A1), the precommunicating part of the posterior cerebral artery (P1) and anterior communicating artery was seen. Hypoplasia of the right and left PcoA was observed in 8 and 5 cases, respectively. Aplasia of the right PcoA was found in 16.6% and of the left PcoA in 3.3%. In this study, we confirmed the previously described finding that the symmetrical, circular configuration of the circulus arteriosus cerebri is present in only about 42.1%. The main differences between the fetal and adult disposition are the diameter of the PcoA and the circular part of the posterior cerebral artery. According to previous studies, the fetal brain older than 4 months has anatomical characteristics very similar to the adult's circle; our finding was mostly similar to adult samples as most samples were from infants, not fetuses. (c) 2008 S. Karger AG, Basel.

When tractography meets tracer injections: a systematic study of trends and variation sources of diffusion-based connectivity.

PubMed

Aydogan, Dogu Baran; Jacobs, Russell; Dulawa, Stephanie; Thompson, Summer L; Francois, Maite Christi; Toga, Arthur W; Dong, Hongwei; Knowles, James A; Shi, Yonggang

2018-04-16

Tractography is a powerful technique capable of non-invasively reconstructing the structural connections in the brain using diffusion MRI images, but the validation of tractograms is challenging due to lack of ground truth. Owing to recent developments in mapping the mouse brain connectome, high-resolution tracer injection-based axonal projection maps have been created and quickly adopted for the validation of tractography. Previous studies using tracer injections mainly focused on investigating the match in projections and optimal tractography protocols. Being a complicated technique, however, tractography relies on multiple stages of operations and parameters. These factors introduce large variabilities in tractograms, hindering the optimization of protocols and making the interpretation of results difficult. Based on this observation, in contrast to previous studies, in this work we focused on quantifying and ranking the amount of performance variation introduced by these factors. For this purpose, we performed over a million tractography experiments and studied the variability across different subjects, injections, anatomical constraints and tractography parameters. By using N-way ANOVA analysis, we show that all tractography parameters are significant and importantly performance variations with respect to the differences in subjects are comparable to the variations due to tractography parameters, which strongly underlines the importance of fully documenting the tractography protocols in scientific experiments. We also quantitatively show that inclusion of anatomical constraints is the most significant factor for improving tractography performance. Although this critical factor helps reduce false positives, our analysis indicates that anatomy-informed tractography still fails to capture a large portion of axonal projections.

Variations in xylem embolism susceptibility under drought between intact saplings of three walnut species.

PubMed

Knipfer, Thorsten; Barrios-Masias, Felipe H; Cuneo, Italo F; Bouda, Martin; Albuquerque, Caetano P; Brodersen, Craig R; Kluepfel, Daniel A; McElrone, Andrew J

2018-05-30

A germplasm collection containing varied Juglans genotypes holds potential to improve drought resistance of plant materials for commercial production. We used X-ray computed microtomography to evaluate stem xylem embolism susceptibility/repair in relation to vessel anatomical features (size, arrangement, connectivity and pit characteristics) in 2-year-old saplings of three Juglans species. In vivo analysis revealed interspecific variations in embolism susceptibility among Juglans microcarpa, J. hindsii (both native to arid habitats) and J. ailantifolia (native to mesic habitats). Stem xylem of J. microcarpa was more resistant to drought-induced embolism as compared with J. hindsii and J. ailantifolia (differences in embolism susceptibility among older and current year xylem were not detected in any species). Variations in most vessel anatomical traits were negligible among the three species; however, we detected substantial interspecific differences in intervessel pit characteristics. As compared with J. hindsii and J. ailantifolia, low embolism susceptibility in J. microcarpa was associated with smaller pit size in larger diameter vessels, a smaller area of the shared vessel wall occupied by pits, lower pit frequency and no changes in pit characteristics as vessel diameters increased. Changes in amount of embolized vessels following 40 days of re-watering were minor in intact saplings of all three species highlighting that an embolism repair mechanism did not contribute to drought recovery. In conclusion, our data indicate that interspecific variations in drought-induced embolism susceptibility are associated with species-specific pit characteristics, and these traits may provide a future target for breeding efforts aimed at selecting walnut germplasm with improved drought resistance.

Structural and Functional Bases for Individual Differences in Motor Learning

PubMed Central

Tomassini, Valentina; Jbabdi, Saad; Kincses, Zsigmond T.; Bosnell, Rose; Douaud, Gwenaelle; Pozzilli, Carlo; Matthews, Paul M.; Johansen-Berg, Heidi

2013-01-01

People vary in their ability to learn new motor skills. We hypothesize that between-subject variability in brain structure and function can explain differences in learning. We use brain functional and structural MRI methods to characterize such neural correlates of individual variations in motor learning. Healthy subjects applied isometric grip force of varying magnitudes with their right hands cued visually to generate smoothly-varying pressures following a regular pattern. We tested whether individual variations in motor learning were associated with anatomically colocalized variations in magnitude of functional MRI (fMRI) signal or in MRI differences related to white and grey matter microstructure. We found that individual motor learning was correlated with greater functional activation in the prefrontal, premotor, and parietal cortices, as well as in the basal ganglia and cerebellum. Structural MRI correlates were found in the premotor cortex [for fractional anisotropy (FA)] and in the cerebellum [for both grey matter density and FA]. The cerebellar microstructural differences were anatomically colocalized with fMRI correlates of learning. This study thus suggests that variations across the population in the function and structure of specific brain regions for motor control explain some of the individual differences in skill learning. This strengthens the notion that brain structure determines some limits to cognitive function even in a healthy population. Along with evidence from pathology suggesting a role for these regions in spontaneous motor recovery, our results also highlight potential targets for therapeutic interventions designed to maximize plasticity for recovery of similar visuomotor skills after brain injury. PMID:20533562

Accuracy of femoral templating in reproducing anatomical femoral offset in total hip replacement.

PubMed

Davies, H; Foote, J; Spencer, R F

2007-01-01

Restoration of hip biomechanics is a crucial component of successful total hip replacement. Preoperative templating is recommended to ensure that the size and orientation of implants is optimised. We studied how closely natural femoral offset could be reproduced using the manufacturers' templates for 10 femoral stems in common use in the UK. A series of 23 consecutive preoperative radiographs from patients who had undergone unilateral total hip replacement for unilateral osteoarthritis of the hip was employed. The change in offset between the templated position of the best-fitting template and the anatomical centre of the hip was measured. The templates were then ranked according to their ability to reproduce the normal anatomical offset. The most accurate was the CPS-Plus (Root Mean Square Error 2.0 mm) followed in rank order by: C stem (2.16), CPT (2.40), Exeter (3.23), Stanmore (3.28), Charnley (3.65), Corail (3.72), ABG II (4.30), Furlong HAC (5.08) and Furlong modular (7.14). A similar pattern of results was achieved when the standard error of variability of offset was analysed. We observed a wide variation in the ability of the femoral prosthesis templates to reproduce normal femoral offset. This variation was independent of the seniority of the observer. The templates of modern polished tapered stems with high modularity were best able to reproduce femoral offset. The current move towards digitisation of X-rays may offer manufacturers an opportunity to improve template designs in certain instances, and to develop appropriate computer software.

The structure of the perivascular compartment in the old canine brain: a case study.

PubMed

Criswell, Theodore P; Sharp, Matthew MacGregor; Dobson, Howard; Finucane, Ciara; Weller, Roy O; Verma, Ajay; Carare, Roxana O

2017-11-15

Dilatation of periarteriolar spaces in MRI of the ageing human brains occurs in white matter (WM), basal ganglia and midbrain but not in cerebral cortex. Perivenous collagenous occurs in periventricular but not in subcortical WM.Here we test the hypotheses that (a) the capacity for dilatation of periarteriolar spaces correlates with the anatomical distribution of leptomeningeal cells coating intracerebral arteries and (b) the regional development of perivenous collagenous in the WM correlates with the population of intramural cells in the walls of veins.The anatomical distribution of leptomeningeal and intramural cells related to cerebral blood vessels is best documented by electron microscopy, requiring perfusion-fixed tissue not available in human material. We therefore analysed perfusion-fixed brain from a 12-year-old Beagle dog as the canine brain represents the anatomical arrangement in the human brain. Results showed regional variation in the arrangement of leptomeningeal cells around blood vessels. Arterioles are enveloped by one complete layer of leptomeninges often with a second incomplete layer in the WM. Venules showed incomplete layers of leptomeningeal cells. Intramural cell expression was higher in the post-capillary venules of the subcortical WM when compared with periventricular WM, suggesting that periventricular collagenosis around venules may be due to a lower resistance in the venular walls. It appears that the regional variation in the capacity for dilatation of arteriolar perivascular spaces in the white WM may be related to the number of perivascular leptomeningeal cells surrounding vessels in different areas of the brain. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.

Effects of instructional strategies using cross sections on the recognition of anatomical structures in correlated CT and MR images.

PubMed

Khalil, Mohammed K; Paas, Fred; Johnson, Tristan E; Su, Yung K; Payer, Andrew F

2008-01-01

This research is an effort to best utilize the interactive anatomical images for instructional purposes based on cognitive load theory. Three studies explored the differential effects of three computer-based instructional strategies that use anatomical cross-sections to enhance the interpretation of radiological images. These strategies include: (1) cross-sectional images of the head that can be superimposed on radiological images, (2) transparent highlighting of anatomical structures in radiological images, and (3) cross-sectional images of the head with radiological images presented side-by-side. Data collected included: (1) time spent on instruction and on solving test questions, (2) mental effort during instruction and test, and (3) students' performance to identify anatomical structures in radiological images. Participants were 28 freshmen medical students (15 males and 13 females) and 208 biology students (190 females and 18 males). All studies used posttest-only control group design, and the collected data were analyzed by either t test or ANOVA. In self-directed computer-based environments, the strategies that used cross sections to improve students' ability to recognize anatomic structures in radiological images showed no significant positive effects. However, when increasing the complexity of the instructional materials, cross-sectional images imposed a higher cognitive load, as indicated by higher investment of mental effort. There is not enough evidence to claim that the simultaneous combination of cross sections and radiological images has no effect on the identification of anatomical structures in radiological images for novices. Further research that control for students' learning and cognitive style is needed to reach an informative conclusion.

Controlling stimulation strength and focality in electroconvulsive therapy via current amplitude and electrode size and spacing: comparison with magnetic seizure therapy.

PubMed

Deng, Zhi-De; Lisanby, Sarah H; Peterchev, Angel V

2013-12-01

Understanding the relationship between the stimulus parameters of electroconvulsive therapy (ECT) and the electric field characteristics could guide studies on improving risk/benefit ratio. We aimed to determine the effect of current amplitude and electrode size and spacing on the ECT electric field characteristics, compare ECT focality with magnetic seizure therapy (MST), and evaluate stimulus individualization by current amplitude adjustment. Electroconvulsive therapy and double-cone-coil MST electric field was simulated in a 5-shell spherical human head model. A range of ECT electrode diameters (2-5 cm), spacing (1-25 cm), and current amplitudes (0-900 mA) was explored. The head model parameters were varied to examine the stimulus current adjustment required to compensate for interindividual anatomical differences. By reducing the electrode size, spacing, and current, the ECT electric field can be more focal and superficial without increasing scalp current density. By appropriately adjusting the electrode configuration and current, the ECT electric field characteristics can be made to approximate those of MST within 15%. Most electric field characteristics in ECT are more sensitive to head anatomy variation than in MST, especially for close electrode spacing. Nevertheless, ECT current amplitude adjustment of less than 70% can compensate for interindividual anatomical variability. The strength and focality of ECT can be varied over a wide range by adjusting the electrode size, spacing, and current. If desirable, ECT can be made as focal as MST while using simpler stimulation equipment. Current amplitude individualization can compensate for interindividual anatomical variability.

Networks of myelin covariance

PubMed Central

Slater, David; Ruef, Anne; Sanabria‐Diaz, Gretel; Preisig, Martin; Kherif, Ferath; Draganski, Bogdan; Lutti, Antoine

2017-01-01

Abstract Networks of anatomical covariance have been widely used to study connectivity patterns in both normal and pathological brains based on the concurrent changes of morphometric measures (i.e., cortical thickness) between brain structures across subjects (Evans, 2013). However, the existence of networks of microstructural changes within brain tissue has been largely unexplored so far. In this article, we studied in vivo the concurrent myelination processes among brain anatomical structures that gathered together emerge to form nonrandom networks. We name these “networks of myelin covariance” (Myelin‐Nets). The Myelin‐Nets were built from quantitative Magnetization Transfer data—an in‐vivo magnetic resonance imaging (MRI) marker of myelin content. The synchronicity of the variations in myelin content between anatomical regions was measured by computing the Pearson's correlation coefficient. We were especially interested in elucidating the effect of age on the topological organization of the Myelin‐Nets. We therefore selected two age groups: Young‐Age (20–31 years old) and Old‐Age (60–71 years old) and a pool of participants from 48 to 87 years old for a Myelin‐Nets aging trajectory study. We found that the topological organization of the Myelin‐Nets is strongly shaped by aging processes. The global myelin correlation strength, between homologous regions and locally in different brain lobes, showed a significant dependence on age. Interestingly, we also showed that the aging process modulates the resilience of the Myelin‐Nets to damage of principal network structures. In summary, this work sheds light on the organizational principles driving myelination and myelin degeneration in brain gray matter and how such patterns are modulated by aging. PMID:29271053

Bouldering: an alternative strategy to long-vertical climbing in root-climbing hortensias

PubMed Central

Granados Mendoza, Carolina; Isnard, Sandrine; Charles-Dominique, Tristan; Van den Bulcke, Jan; Rowe, Nick P.; Van Acker, Joris; Goetghebeur, Paul; Samain, Marie-Stéphanie

2014-01-01

In the Neotropics, the genus Hydrangea of the popular ornamental hortensia family is represented by climbing species that strongly cling to their support surface by means of adhesive roots closely positioned along specialized anchoring stems. These root-climbing hortensia species belong to the nearly exclusive American Hydrangea section Cornidia and generally are long lianescent climbers that mostly flower and fructify high in the host tree canopy. The Mexican species Hydrangea seemannii, however, encompasses not only long lianescent climbers of large vertical rock walls and coniferous trees, but also short ‘shrub-like’ climbers on small rounded boulders. To investigate growth form plasticity in root-climbing hortensia species, we tested the hypothesis that support variability (e.g. differences in size and shape) promotes plastic responses observable at the mechanical, structural and anatomical level. Stem bending properties, architectural axis categorization, tissue organization and wood density were compared between boulder and long-vertical tree-climbers of H. seemannii. For comparison, the mechanical patterns of a closely related, strictly long-vertical tree-climbing species were investigated. Hydrangea seemannii has fine-tuned morphological, mechanical and anatomical responses to support variability suggesting the presence of two alternative root-climbing strategies that are optimized for their particular environmental conditions. Our results suggest that variation of some stem anatomical traits provides a buffering effect that regulates the mechanical and hydraulic demands of two distinct plant architectures. The adaptive value of observed plastic responses and the importance of considering growth form plasticity in evolutionary and conservation studies are discussed. PMID:25079869

[Sacroiliac joint injury treated with oblique insertion at anatomical points: a randomized controlled trial].

PubMed

Kuang, Jiayi; Li, Yuxuan; He, Yufeng; Gan, Lin; Wang, Aiming; Chen, Yanhua; Li, Xiaoting; Guo, Lin; Tang, Rongjun

2016-04-01

To compare the effects of oblique insertion at anatomical points and conventional acupuncture for sacroiliac joint injury. Eighty patients were randomly divided into an observation group and a control group, 40 cases in each one. In the observation group, oblique insertion therapy at anatomical points was used, and the 9 points of equal division (anatomical points) marked by palpating the anatomical symbol were treated as the insertion acupoints. In the control group, conventional acupuncture was applied, and perpendicular insertion was adopted at Huantiao (GB 30), Zhibian (BL 54) and Weizhong (BL 40), etc. In the two groups, the! treatment was given once a day and 5 times per week. Ten treatments were made into one course and two courses were required. The clinical effects, the changes of visual analogue scale (VAS) and Oswestry dysfunctional index. (ODI) before and after treatment were observed in the two groups. The total effective rate of the observation group was 90.0% (36/40), which was better than 72.5% (29/40) of the control group (P < 0.05). After treatment, the results of the VAS and ODI of the two groups were apparently declined (both P < 0.01), and those in the observation group were decreased more obviously (both P < 0.01). The effect of oblique inser-tion at anatomical points for sacroiliac joint injury is superior to that of conventional acupuncture, which can effectively relieve pain and improve the disfunction.

Anatomy and genetic diversity of two populations of Schinus terebinthifolius (Anacardiaceae) from the Tibagi River basin in Paraná, Brazil.

PubMed

Ruas, E A; Ruas, C F; Medri, P S; Medri, C; Medri, M E; Bianchini, E; Pimenta, J A; Rodrigues, L A; Ruas, P M

2011-03-29

Knowledge of the effects of flooding on plant survival is relevant for the efficiency of management and conservation programs. Schinus terebinthifolius is a tree of economic and ecological importance that is common in northeast Brazil. Flooding tolerance and genetic variation were investigated in two riparian populations of S. terebinthifolius distributed along two different ecological regions of the Tibagi River basin. Flooding tolerance was evaluated through the investigation of young plants, submitted to different flooding intensities to examine the morphological and anatomical responses to this stress. The growth rate of S. terebinthifolius was not affected by flooding, but total submersion proved to be lethal for 100% of the plants. Morphological alterations such as hypertrophied lenticels were observed in both populations and lenticel openings were significantly higher in plants from one population. Genetic analysis using DNA samples obtained from both populations showed a moderate degree of genetic variation between populations (13.7%); most of the variation was found within populations (86.3%). These results show that for conservation purposes and management of degraded areas, both populations should be preserved and could be used in programs that intend to recompose riparian forests.

Anatomical classification of breast sentinel lymph nodes using computed tomography-lymphography.

PubMed

Fujita, Tamaki; Miura, Hiroyuki; Seino, Hiroko; Ono, Shuichi; Nishi, Takashi; Nishimura, Akimasa; Hakamada, Kenichi; Aoki, Masahiko

2018-05-03

To evaluate the anatomical classification and location of breast sentinel lymph nodes, preoperative computed tomography-lymphography examinations were retrospectively reviewed for sentinel lymph nodes in 464 cases clinically diagnosed with node-negative breast cancer between July 2007 and June 2016. Anatomical classification was performed based on the numbers of lymphatic routes and sentinel lymph nodes, the flow direction of lymphatic routes, and the location of sentinel lymph nodes. Of the 464 cases reviewed, anatomical classification could be performed in 434 (93.5 %). The largest number of cases showed single route/single sentinel lymph node (n = 296, 68.2 %), followed by multiple routes/multiple sentinel lymph nodes (n = 59, 13.6 %), single route/multiple sentinel lymph nodes (n = 53, 12.2 %), and multiple routes/single sentinel lymph node (n = 26, 6.0 %). Classification based on the flow direction of lymphatic routes showed that 429 cases (98.8 %) had outward flow on the superficial fascia toward axillary lymph nodes, whereas classification based on the height of sentinel lymph nodes showed that 323 cases (74.4 %) belonged to the upper pectoral group of axillary lymph nodes. There was wide variation in the number of lymphatic routes and their branching patterns and in the number, location, and direction of flow of sentinel lymph nodes. It is clinically very important to preoperatively understand the anatomical morphology of lymphatic routes and sentinel lymph nodes for optimal treatment of breast cancer, and computed tomography-lymphography is suitable for this purpose.

Hox control of Drosophila larval anatomy; The Alary and Thoracic Alary-Related Muscles.

PubMed

Bataillé, Laetitia; Frendo, Jean-Louis; Vincent, Alain

2015-11-01

The body plan of arthropods and vertebrates involves the formation of repetitive segments, which subsequently diversify to give rise to different body parts along the antero-posterior/rostro-caudal body axis. Anatomical variations between body segments are crucial for organ function and organismal fitness. Pioneering work in Drosophila has established that Hox transcription factors play key roles both in endowing initially identical segments with distinct identities and organogenesis. The focus of this review is on Alary Muscles (AMs) and the newly discovered Thoracic Alary-Related Muscles (TARMs). AMs and TARMs are thin muscles which together connect the circulatory system and different midgut regions to the exoskeleton, while intertwining with the respiratory tubular network. They were hypothesized to represent a new type of muscles with spring-like properties, maintaining internal organs in proper anatomical positions during larval locomotion. Both the morphology of TARMs relative to AMs, and morphogenesis of connected tissues is under Hox control, emphasizing the key role of Hox proteins in coordinating the anatomical development of the larva. Copyright © 2015 Elsevier B.V. All rights reserved.

Anatomical and functional characteristics of carotid sinus stimulation in humans

NASA Technical Reports Server (NTRS)

Querry, R. G.; Smith, S. A.; Stromstad, M.; Ide, K.; Secher, N. H.; Raven, P. B.

2001-01-01

Transmission characteristics of pneumatic pressure to the carotid sinus were evaluated in 19 subjects at rest and during exercise. Either a percutaneous fluid-filled (n = 12) or balloon-tipped catheter (n = 7) was placed at the carotid bifurcation to record internal transmission of external neck pressure/neck suction (NP/NS). Sustained, 5-s pulses, and rapid ramping pulse protocols (+40 to -80 Torr) were recorded. Transmission of pressure stimuli was less with the fluid-filled catheter compared with that of the balloon-tipped catheter (65% vs. 82% negative pressure, 83% vs. 89% positive pressure; P < 0.05). Anatomical location of the carotid sinus averaged 3.2 cm (left) and 3.6 cm (right) from the gonion of the mandible with a range of 0-7.5 cm. Transmission was not altered by exercise or Valsalva maneuver, but did vary depending on the position of the carotid sinus locus beneath the sealed chamber. These data indicate that transmission of external NP/NS was higher than previously recorded in humans, and anatomical variation of carotid sinus location and equipment design can affect transmission results.

Anatomically ordered tapping interferes more with one-digit addition than two-digit addition: a dual-task fMRI study.

PubMed

Soylu, Firat; Newman, Sharlene D

2016-02-01

Fingers are used as canonical representations for numbers across cultures. In previous imaging studies, it was shown that arithmetic processing activates neural resources that are known to participate in finger movements. Additionally, in one dual-task study, it was shown that anatomically ordered finger tapping disrupts addition and subtraction more than multiplication, possibly due to a long-lasting effect of early finger counting experiences on the neural correlates and organization of addition and subtraction processes. How arithmetic task difficulty and tapping complexity affect the concurrent performance is still unclear. If early finger counting experiences have bearing on the neural correlates of arithmetic in adults, then one would expect anatomically and non-anatomically ordered tapping to have different interference effects, given that finger counting is usually anatomically ordered. To unravel these issues, we studied how (1) arithmetic task difficulty and (2) the complexity of the finger tapping sequence (anatomical vs. non-anatomical ordering) affect concurrent performance and use of key neural circuits using a mixed block/event-related dual-task fMRI design with adult participants. The results suggest that complexity of the tapping sequence modulates interference on addition, and that one-digit addition (fact retrieval), compared to two-digit addition (calculation), is more affected from anatomically ordered tapping. The region-of-interest analysis showed higher left angular gyrus BOLD response for one-digit compared to two-digit addition, and in no-tapping conditions than dual tapping conditions. The results support a specific association between addition fact retrieval and anatomically ordered finger movements in adults, possibly due to finger counting strategies that deploy anatomically ordered finger movements early in the development.

Bayesian denoising in digital radiography: a comparison in the dental field.

PubMed

Frosio, I; Olivieri, C; Lucchese, M; Borghese, N A; Boccacci, P

2013-01-01

We compared two Bayesian denoising algorithms for digital radiographs, based on Total Variation regularization and wavelet decomposition. The comparison was performed on simulated radiographs with different photon counts and frequency content and on real dental radiographs. Four different quality indices were considered to quantify the quality of the filtered radiographs. The experimental results suggested that Total Variation is more suited to preserve fine anatomical details, whereas wavelets produce images of higher quality at global scale; they also highlighted the need for more reliable image quality indices. Copyright © 2012 Elsevier Ltd. All rights reserved.

Hormone response to bidirectional selection on social behavior.

PubMed

Amdam, Gro V; Page, Robert E; Fondrk, M Kim; Brent, Colin S

2010-01-01

Behavior is a quantitative trait determined by multiple genes. Some of these genes may have effects from early development and onward by influencing hormonal systems that are active during different life-stages leading to complex associations, or suites, of traits. Honey bees (Apis mellifera) have been used extensively in experiments on the genetic and hormonal control of complex social behavior, but the relationships between their early developmental processes and adult behavioral variation are not well understood. Bidirectional selective breeding on social food-storage behavior produced two honey bee strains, each with several sublines, that differ in an associated suite of anatomical, physiological, and behavioral traits found in unselected wild type bees. Using these genotypes, we document strain-specific changes during larval, pupal, and early adult life-stages for the central insect hormones juvenile hormone (JH) and ecdysteroids. Strain differences correlate with variation in female reproductive anatomy (ovary size), which can be influenced by JH during development, and with secretion rates of ecdysteroid from the ovaries of adults. Ovary size was previously assigned to the suite of traits of honey bee food-storage behavior. Our findings support that bidirectional selection on honey bee social behavior acted on pleiotropic gene networks. These networks may bias a bee's adult phenotype by endocrine effects on early developmental processes that regulate variation in reproductive traits. © 2010 Wiley Periodicals, Inc.

Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation.

PubMed

Araújo, Márcio S; Perez, S Ivan; Magazoni, Maria Julia C; Petry, Ana C

2014-12-04

Phenotypic diversity among populations may result from divergent natural selection acting directly on traits or via correlated responses to changes in other traits. One of the most frequent patterns of correlated response is the proportional change in the dimensions of anatomical traits associated with changes in growth or absolute size, known as allometry. Livebearing fishes subject to predation gradients have been shown to repeatedly evolve larger caudal peduncles and smaller cranial regions under high predation regimes. Poecilia vivipara is a livebearing fish commonly found in coastal lagoons in the north of the state of Rio de Janeiro, Brazil. Similar to what is observed in other predation gradients, lagoons inhabited by P. vivipara vary in the presence of piscivorous fishes; contrary to other poeciliid systems, populations of P. vivipara vary greatly in body size, which opens the possibility of strong allometric effects on shape variation. Here we investigated body shape diversification among six populations of P. vivipara along a predation gradient and its relationship with allometric trajectories within and among populations. We found substantial body size variation and correlated shape changes among populations. Multivariate regression analysis showed that size variation among populations accounted for 66% of shape variation in females and 38% in males, suggesting that size is the most important dimension underlying shape variation among populations of P. vivipara in this system. Changes in the relative sizes of the caudal peduncle and cranial regions were only partly in line with predictions from divergent natural selection associated with predation regime. Our results suggest the possibility that adaptive shape variation among populations has been partly constrained by allometry in P. vivipara. Processes governing body size changes are therefore important in the diversification of this species. We conclude that in species characterized by substantial among-population differences in body size, ignoring allometric effects when investigating divergent natural selection's role in phenotypic diversification might not be warranted.

Joint brain connectivity estimation from diffusion and functional MRI data

NASA Astrophysics Data System (ADS)

Chu, Shu-Hsien; Lenglet, Christophe; Parhi, Keshab K.

2015-03-01

Estimating brain wiring patterns is critical to better understand the brain organization and function. Anatomical brain connectivity models axonal pathways, while the functional brain connectivity characterizes the statistical dependencies and correlation between the activities of various brain regions. The synchronization of brain activity can be inferred through the variation of blood-oxygen-level dependent (BOLD) signal from functional MRI (fMRI) and the neural connections can be estimated using tractography from diffusion MRI (dMRI). Functional connections between brain regions are supported by anatomical connections, and the synchronization of brain activities arises through sharing of information in the form of electro-chemical signals on axon pathways. Jointly modeling fMRI and dMRI data may improve the accuracy in constructing anatomical connectivity as well as functional connectivity. Such an approach may lead to novel multimodal biomarkers potentially able to better capture functional and anatomical connectivity variations. We present a novel brain network model which jointly models the dMRI and fMRI data to improve the anatomical connectivity estimation and extract the anatomical subnetworks associated with specific functional modes by constraining the anatomical connections as structural supports to the functional connections. The key idea is similar to a multi-commodity flow optimization problem that minimizes the cost or maximizes the efficiency for flow configuration and simultaneously fulfills the supply-demand constraint for each commodity. In the proposed network, the nodes represent the grey matter (GM) regions providing brain functionality, and the links represent white matter (WM) fiber bundles connecting those regions and delivering information. The commodities can be thought of as the information corresponding to brain activity patterns as obtained for instance by independent component analysis (ICA) of fMRI data. The concept of information flow is introduced and used to model the propagation of information between GM areas through WM fiber bundles. The link capacity, i.e., ability to transfer information, is characterized by the relative strength of fiber bundles, e.g., fiber count gathered from the tractography of dMRI data. The node information demand is considered to be proportional to the correlation between neural activity at various cortical areas involved in a particular functional mode (e.g. visual, motor, etc.). These two properties lead to the link capacity and node demand constraints in the proposed model. Moreover, the information flow of a link cannot exceed the demand from either end node. This is captured by the feasibility constraints. Two different cost functions are considered in the optimization formulation in this paper. The first cost function, the reciprocal of fiber strength represents the unit cost for information passing through the link. In the second cost function, a min-max (minimizing the maximal link load) approach is used to balance the usage of each link. Optimizing the first cost function selects the pathway with strongest fiber strength for information propagation. In the second case, the optimization procedure finds all the possible propagation pathways and allocates the flow proportionally to their strength. Additionally, a penalty term is incorporated with both the cost functions to capture the possible missing and weak anatomical connections. With this set of constraints and the proposed cost functions, solving the network optimization problem recovers missing and weak anatomical connections supported by the functional information and provides the functional-associated anatomical subnetworks. Feasibility is demonstrated using realistic diffusion and functional MRI phantom data. It is shown that the proposed model recovers the maximum number of true connections, with fewest number of false connections when compared with the connectivity derived from a joint probabilistic model using the expectation-maximization (EM) algorithm presented in a prior work. We also apply the proposed method to data provided by the Human Connectome Project (HCP).

Applied anatomy of the pterygomandibular space: improving the success of inferior alveolar nerve blocks.

PubMed

Khoury, J N; Mihailidis, S; Ghabriel, M; Townsend, G

2011-06-01

A thorough knowledge of the anatomy of the pterygomandibular space is essential for the successful administration of the inferior alveolar nerve block. In addition to the inferior alveolar and lingual nerves, other structures in this space are of particular significance for local anaesthesia, including the inferior alveolar vessels, the sphenomandibular ligament and the interpterygoid fascia. These structures can all potentially have an impact on the effectiveness of local anaesthesia in this area. Greater understanding of the nature and extent of variation in intraoral landmarks and underlying structures should lead to improved success rates, and provide safer and more effective anaesthesia. The direct technique for the inferior alveolar nerve block is used frequently by most clinicians in Australia and this review evaluates its anatomical rationale and provides possible explanations for anaesthetic failures. © 2011 Australian Dental Association.

Creation of anatomical models from CT data

NASA Astrophysics Data System (ADS)

Alaytsev, Innokentiy K.; Danilova, Tatyana V.; Manturov, Alexey O.; Mareev, Gleb O.; Mareev, Oleg V.

2018-04-01

Computed tomography is a great source of biomedical data because it allows a detailed exploration of complex anatomical structures. Some structures are not visible on CT scans, and some are hard to distinguish due to partial volume effect. CT datasets require preprocessing before using them as anatomical models in a simulation system. The work describes segmentation and data transformation methods for an anatomical model creation from the CT data. The result models may be used for visual and haptic rendering and drilling simulation in a virtual surgery system.

A COMPARATIVE INVESTIGATION OF THE INFLUENCE OF DERMAL APPENDAGES (HAIR FOLLICLES) ON THE PERCUTANEOUS ABSORPTION OF ORGANOPHOSPHORUS (OP) INSECTICIDES USING QSAR AND PBPK/PD MODELS FOR HUMAN RISK ASSESSMENT

EPA Science Inventory

The successful use of the Exposure Related Dose Estimating Model (ERDEM) for assessment of dermal exposure of humans to OP pesticides requires the input of representative and comparable input parameters. In the specific case of dermal exposure, regional anatomical variation in...

Stereoscopic Vascular Models of the Head and Neck: A Computed Tomography Angiography Visualization

ERIC Educational Resources Information Center

Cui, Dongmei; Lynch, James C.; Smith, Andrew D.; Wilson, Timothy D.; Lehman, Michael N.

2016-01-01

Computer-assisted 3D models are used in some medical and allied health science schools; however, they are often limited to online use and 2D flat screen-based imaging. Few schools take advantage of 3D stereoscopic learning tools in anatomy education and clinically relevant anatomical variations when teaching anatomy. A new approach to teaching…

Task demands affect spatial reference frame weighting during tactile localization in sighted and congenitally blind adults

PubMed Central

Schubert, Jonathan T. W.; Badde, Stephanie; Röder, Brigitte

2017-01-01

Task demands modulate tactile localization in sighted humans, presumably through weight adjustments in the spatial integration of anatomical, skin-based, and external, posture-based information. In contrast, previous studies have suggested that congenitally blind humans, by default, refrain from automatic spatial integration and localize touch using only skin-based information. Here, sighted and congenitally blind participants localized tactile targets on the palm or back of one hand, while ignoring simultaneous tactile distractors at congruent or incongruent locations on the other hand. We probed the interplay of anatomical and external location codes for spatial congruency effects by varying hand posture: the palms either both faced down, or one faced down and one up. In the latter posture, externally congruent target and distractor locations were anatomically incongruent and vice versa. Target locations had to be reported either anatomically (“palm” or “back” of the hand), or externally (“up” or “down” in space). Under anatomical instructions, performance was more accurate for anatomically congruent than incongruent target-distractor pairs. In contrast, under external instructions, performance was more accurate for externally congruent than incongruent pairs. These modulations were evident in sighted and blind individuals. Notably, distractor effects were overall far smaller in blind than in sighted participants, despite comparable target-distractor identification performance. Thus, the absence of developmental vision seems to be associated with an increased ability to focus tactile attention towards a non-spatially defined target. Nevertheless, that blind individuals exhibited effects of hand posture and task instructions in their congruency effects suggests that, like the sighted, they automatically integrate anatomical and external information during tactile localization. Moreover, spatial integration in tactile processing is, thus, flexibly adapted by top-down information—here, task instruction—even in the absence of developmental vision. PMID:29228023

Anatomic Variations of the Anterior Atlantodental Joint and Relations to the Apical and Alar Ligaments in a Geriatric Population.

PubMed

Rustagi, Tarush; Iwanaga, Joe; Sardi, Juan P; Alonso, Fernando; Oskouian, Rod J; Tubbs, R Shane

2017-11-01

Degenerative changes in the upper cervical spine may be age related degeneration or a pathological process such as rheumatoid arthritis. However, to our knowledge, the relationship between the apical and alar ligaments and these anomalies has not been discussed. We present anatomical variations of the anterior atlantodental joint observed during cadaveric dissection of adult craniovertebral junctions, the relationship with the alar and apical ligaments and discuss possible origins and clinical implications. The upper cervical spine including part of the occiput was dissected from cadavers whose mean age at death was 78.9 years-old. The anterior atlantodental joint and apical and alar ligaments were observed and any atypical findings were noted. In eleven specimens, seven had a dens corona, three had an os odontoideum and one had a dens aureola, which arose from the upper part of the anterior arch of the atlas. Only four specimens had an apical ligament. The possible etiologies and the clinical applications of these craniovertebral anomalies in a geriatric population should be appreciated by the clinician treating patients with disease in this area or interpreting imaging in the region. Copyright © 2017 Elsevier Inc. All rights reserved.

Evaluation of vascular variations at cerebellopontine angle by 3D T2WI magnetic-resonance imaging in patients with vertigo.

PubMed

Beyazal Celiker, Fatma; Dursun, Engin; Celiker, Metin; Durakoglugil, Tugba; Beyazal, Mehmet; Inecikli, Mehmet Fatih; Ozgur, Abdulkadir; Terzi, Suat

2017-01-01

Vascular loops of the anterior-inferior cerebellar artery (AICA) at the cerebellopontine angle (CPA) are considered related to auditory-vestibular symptoms. Clinical association of these anatomical aberrations, which can be grouped together as vascular compression syndromes, is controversial. Magnetic resonance imaging (MRI) is widely used to visualize this anatomical region, given its high sensitivity and specificity. To elucidate the clinical relationship of vertigo symptoms with vascular loop compression syndrome by evaluating the neurovascular contacts of the vestibulocochlear nerve (VCN) and AICA at the CPA and internal auditory canal via high-resolution MRI. The study included 417 patients (178 with vertigo and 239 without vertigo) undergoing MRI for various clinical causes. MRI scans were assessed to study the presence of vascular abnormalities at the CPA. According to our findings, type 1 vascular variation was observed most frequently in both sides. MRI findings were similar for the patients with and without vertigo. Identifying the prevalence of the vascular loops of the AICA primarily depends on diagnostic technique, and our results identified a slightly higher prevalence than those of previous studies, which might be partly related to the high-sensitivity of 3-dimensional T2-weighted MRI.

Antegrade Sclerotherapy to Treat All Types of Varicoceles in the Pediatric Population: Experience of a Single Center.

PubMed

Paradiso, Filomena Valentina; Mason, Elena Jane; Nanni, Lorenzo

2016-12-01

To analyze our experience with antegrade sclerotherapy for the treatment of Coolsaet types I, II, and III varicoceles in a pediatric and adolescent population. Between 2005 and 2015, 73 patients who underwent antegrade sclerotherapy were retrospectively evaluated. Patient age, side, clinical and Doppler ultrasound grade, and anatomical variations were collected. Varicoceles were grouped following Coolsaet's classification: all types were sclerosed. Follow-up consisted in clinical examination 3 and 6 months following surgery and testicular Doppler ultrasound 6 and 12 months following surgery. Patients were then telephonically interviewed. Success was defined as varicocele resolution or reduction to a grade not requiring surgery. Mean patient age was 14.7 years and mean operating time was 50.8 minutes. Based on phlebographic imaging and following Coolsaet's classification, we identified 57 (78.1%) type I, 3 (4.1%) type II, and 13 (17.8%) type III varicoceles. No intraoperative complications were observed. Three patients (4.1%) presented a short-term complication in the form of pampiniform plexus thrombosis; 1 patient also developed wound dehiscence: all complications occurred in Coolsaet type I varicoceles and during surgeon learning curve. No hydrocele occurred. Out of 59 patients with a satisfactory follow-up (range: 14 months-10 years), 2 recurrences occurred, the success rate thus being 96.6%. Tauber's antegrade sclerotherapy is a simple and feasible technique, effective in treating all kinds of varicocele with low complication, recurrence, and persistence rates. Phlebography reveals frequent venous anatomical variations, allows grouping of varicoceles into Coolsaet types, and enables performing of sclerosis safely in all 3 kinds. Copyright © 2016 Elsevier Inc. All rights reserved.

Measurement and comparison of skin dose using OneDose MOSFET and Mobile MOSFET for patients with acute lymphoblastic leukemia

PubMed Central

Mattar, Essam H.; Hammad, Lina F.; Al-Mohammed, Huda I.

2011-01-01

Summary Background Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to bone marrow transplant. It is involved in the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore measuring and monitoring the skin dose during the treatment is important. Two kinds of metal oxide semiconductor field effect transistor (OneDose MOSFET and mobile MOSEFT) dosimeter are used during the treatment delivery to measure the skin dose to specific points and compare it with the target prescribed dose. The objective of this study was to compare the variation of skin dose in patients with acute lymphatic leukemia (ALL) treated with total body irradiation (TBI) using OneDose MOSFET detectors and Mobile MOSFET, and then compare both results with the target prescribed dose. Material/Methods The measurements involved 32 patient’s (16 males, 16 females), aged between 14–30 years, with an average age of 22.41 years. One-Dose MOSFET and Mobile MOSFET dosimetry were performed at 10 different anatomical sites on every patient. Results The results showed there was no variation between skin dose measured with OneDose MOSFET and Mobile MOSFET in all patients. Furthermore, the results showed for every anatomical site selected there was no significant difference in the dose delivered using either OneDose MOSFET detector or Mobile MOSFET as compared to the prescribed dose. Conclusions The study concludes that One-Dose MOSFET detectors and Mobile MOSFET both give a direct read-out immediately after the treatment; therefore both detectors are suitable options when measuring skin dose for total body irradiation treatment. PMID:21709641

Measurement and comparison of skin dose using OneDose MOSFET and Mobile MOSFET for patients with acute lymphoblastic leukemia.

PubMed

Mattar, Essam H; Hammad, Lina F; Al-Mohammed, Huda I

2011-07-01

Total body irradiation is a protocol used to treat acute lymphoblastic leukemia in patients prior to bone marrow transplant. It is involved in the treatment of the whole body using a large radiation field with extended source-skin distance. Therefore measuring and monitoring the skin dose during the treatment is important. Two kinds of metal oxide semiconductor field effect transistor (OneDose MOSFET and mobile MOSEFT) dosimeter are used during the treatment delivery to measure the skin dose to specific points and compare it with the target prescribed dose. The objective of this study was to compare the variation of skin dose in patients with acute lymphatic leukemia (ALL) treated with total body irradiation (TBI) using OneDose MOSFET detectors and Mobile MOSFET, and then compare both results with the target prescribed dose. The measurements involved 32 patient's (16 males, 16 females), aged between 14-30 years, with an average age of 22.41 years. One-Dose MOSFET and Mobile MOSFET dosimetry were performed at 10 different anatomical sites on every patient. The results showed there was no variation between skin dose measured with OneDose MOSFET and Mobile MOSFET in all patients. Furthermore, the results showed for every anatomical site selected there was no significant difference in the dose delivered using either OneDose MOSFET detector or Mobile MOSFET as compared to the prescribed dose. The study concludes that One-Dose MOSFET detectors and Mobile MOSFET both give a direct read-out immediately after the treatment; therefore both detectors are suitable options when measuring skin dose for total body irradiation treatment.

Distilling allometric and environmental information from time series of conduit size: the standardization issue and its relationship to tree hydraulic architecture.

PubMed

Carrer, Marco; von Arx, Georg; Castagneri, Daniele; Petit, Giai

2015-01-01

Trees are among the best natural archives of past environmental information. Xylem anatomy preserves information related to tree allometry and ecophysiological performance, which is not available from the more customary ring-width or wood-density proxy parameters. Recent technological advances make tree-ring anatomy very attractive because time frames of many centuries can now be covered. This calls for the proper treatment of time series of xylem anatomical attributes. In this article, we synthesize current knowledge on the biophysical and physiological mechanisms influencing the short- to long-term variation in the most widely used wood-anatomical feature, namely conduit size. We also clarify the strong mechanistic link between conduit-lumen size, tree hydraulic architecture and height growth. Among the key consequences of these biophysical constraints is the pervasive, increasing trend of conduit size during ontogeny. Such knowledge is required to process time series of anatomical parameters correctly in order to obtain the information of interest. An appropriate standardization procedure is fundamental when analysing long tree-ring-related chronologies. When dealing with wood-anatomical parameters, this is even more critical. Only an interdisciplinary approach involving ecophysiology, wood anatomy and dendrochronology will help to distill the valuable information about tree height growth and past environmental variability correctly. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Cloud-Based Evaluation of Anatomical Structure Segmentation and Landmark Detection Algorithms: VISCERAL Anatomy Benchmarks.

PubMed

Jimenez-Del-Toro, Oscar; Muller, Henning; Krenn, Markus; Gruenberg, Katharina; Taha, Abdel Aziz; Winterstein, Marianne; Eggel, Ivan; Foncubierta-Rodriguez, Antonio; Goksel, Orcun; Jakab, Andras; Kontokotsios, Georgios; Langs, Georg; Menze, Bjoern H; Salas Fernandez, Tomas; Schaer, Roger; Walleyo, Anna; Weber, Marc-Andre; Dicente Cid, Yashin; Gass, Tobias; Heinrich, Mattias; Jia, Fucang; Kahl, Fredrik; Kechichian, Razmig; Mai, Dominic; Spanier, Assaf B; Vincent, Graham; Wang, Chunliang; Wyeth, Daniel; Hanbury, Allan

2016-11-01

Variations in the shape and appearance of anatomical structures in medical images are often relevant radiological signs of disease. Automatic tools can help automate parts of this manual process. A cloud-based evaluation framework is presented in this paper including results of benchmarking current state-of-the-art medical imaging algorithms for anatomical structure segmentation and landmark detection: the VISCERAL Anatomy benchmarks. The algorithms are implemented in virtual machines in the cloud where participants can only access the training data and can be run privately by the benchmark administrators to objectively compare their performance in an unseen common test set. Overall, 120 computed tomography and magnetic resonance patient volumes were manually annotated to create a standard Gold Corpus containing a total of 1295 structures and 1760 landmarks. Ten participants contributed with automatic algorithms for the organ segmentation task, and three for the landmark localization task. Different algorithms obtained the best scores in the four available imaging modalities and for subsets of anatomical structures. The annotation framework, resulting data set, evaluation setup, results and performance analysis from the three VISCERAL Anatomy benchmarks are presented in this article. Both the VISCERAL data set and Silver Corpus generated with the fusion of the participant algorithms on a larger set of non-manually-annotated medical images are available to the research community.

Morphological Variations in the Transverse Venous Sinus Anatomy of Dogs and its Relationship to Skull Landmarks.

PubMed

Carreira, L Miguel; Ferreira, A

2016-08-01

We characterized the anatomical morphology of the transverse venous sinus (TVS) of 69 canine adult cadavers belonging to three groups: brachycephalic (B), dolichocephalic (D) and mesaticephalic (M). In addition, we outlined its path over the skull using five classic human craniometric points (CPs): the asterion (ast), the bregma (b), the glabella (g), the stephanion (st) and the pterion (pt). The study aimed to establish anatomical differences in the TVS between groups and in the relationship between the TVS and skull. We found that TVS anatomy and its relationships to skull landmarks vary markedly between the groups, with similar anatomical arrangements in B and M. The TVS length can be ranked as M < B < D (with D being the biggest), whereas the width can be ranked as M < D < B (with B being the widest) with the right side being smaller than the left. In the B and M groups, the TVS assumes a craniocaudal trajectory that is closer to the lateral skull wall than in D, where the TVS presents a caudocranial direction. By documenting the morphological characteristics of the TVS, we can create a set of anatomical references allowing construction of a basic framework to greatly decrease the probability of TVS injury during neuronavigation procedures when supported by a good knowledge of the skull, brain anatomies and their relationships. © 2015 Blackwell Verlag GmbH.

Historic origin of the "Arcade of Struthers".

PubMed

De Jesus, Ramon; Dellon, A Lee

2003-05-01

John Struthers wrote in 1848 and 1854 about sites of compression of the median nerve from axilla to elbow. He is best known for describing the rare median nerve entrapment by a ligament from a supracondylar process extending to the medial humeral epicondyle. In 1973, observation of ulnar nerve entrapment associated with a midshaft humeral fracture and subsequent anatomic dissections led to the creation of the term "Arcade of Struthers." Review of Struthers' original writings fails to identify either the use of word "arcade" or description of ulnar nerve compression. Review of published anatomic dissections identifies variations in the origin of the medial head of the triceps, not described by Struthers, that may cause failure of an anterior transposition of the ulnar nerve. Continued use of the term "Arcade of Struthers" is historically incorrect.

Facial reconstruction--anatomical art or artistic anatomy?

PubMed

Wilkinson, Caroline

2010-02-01

Facial reconstruction is employed in the context of forensic investigation and for creating three-dimensional portraits of people from the past, from ancient Egyptian mummies and bog bodies to digital animations of J. S. Bach. This paper considers a facial reconstruction method (commonly known as the Manchester method) associated with the depiction and identification of the deceased from skeletal remains. Issues of artistic licence and scientific rigour, in relation to soft tissue reconstruction, anatomical variation and skeletal assessment, are discussed. The need for artistic interpretation is greatest where only skeletal material is available, particularly for the morphology of the ears and mouth, and with the skin for an ageing adult. The greatest accuracy is possible when information is available from preserved soft tissue, from a portrait, or from a pathological condition or healed injury.

Horseshoe kidney: a review of anatomy and pathology.

PubMed

Natsis, Konstantinos; Piagkou, Maria; Skotsimara, Antonia; Protogerou, Vassilis; Tsitouridis, Ioannis; Skandalakis, Panagiotis

2014-08-01

Horseshoe kidney (HSK) is the most common renal fusion, which is characterized by three anatomic anomalies: ectopia, malrotation and vascular changes. Patients with HSK are prone to a variety of complications, genitourinary and non-genitourinary. In this paper, the anatomy of HSK is delineated with a great emphasis on its blood supply. After reviewing the literature, the arterial supply patterns found by each author were categorized according to the classification system proposed by Graves. The majority of HSKs were found to be supplied by renal arteries derived from the abdominal aorta below the isthmus or by vessels originating from the common iliac arteries. In addition, the abnormalities associated with HSK are highlighted and classified in anatomical variations, congenital anomalies as well as in pathologic conditions related to HSK.

Cardiovascular cast model fabrication and casting effectiveness evaluation in fetus with severe congenital heart disease or normal heart.

PubMed

Wang, Yu; Cao, Hai-yan; Xie, Ming-xing; He, Lin; Han, Wei; Hong, Liu; Peng, Yuan; Hu, Yun-fei; Song, Ben-cai; Wang, Jing; Wang, Bin; Deng, Cheng

2016-04-01

To investigate the application and effectiveness of vascular corrosion technique in preparing fetal cardiovascular cast models, 10 normal fetal heart specimens with other congenital disease (control group) and 18 specimens with severe congenital heart disease (case group) from induced abortions were enrolled in this study from March 2013 to June 2015 in our hospital. Cast models were prepared by injecting casting material into vascular lumen to demonstrate real geometries of fetal cardiovascular system. Casting effectiveness was analyzed in terms of local anatomic structures and different anatomical levels (including overall level, atrioventricular and great vascular system, left-sided and right-sided heart), as well as different trimesters of pregnancy. In our study, all specimens were successfully casted. Casting effectiveness analysis of local anatomic structures showed a mean score from 1.90±1.45 to 3.60±0.52, without significant differences between case and control groups in most local anatomic structures except left ventricle, which had a higher score in control group (P=0.027). Inter-group comparison of casting effectiveness in different anatomical levels showed no significant differences between the two groups. Intra-group comparison also revealed undifferentiated casting effectiveness between atrioventricular and great vascular system, or left-sided and right-sided heart in corresponding group. Third-trimester group had a significantly higher perfusion score in great vascular system than second-trimester group (P=0.046), while the other anatomical levels displayed no such difference. Vascular corrosion technique can be successfully used in fabrication of fetal cardiovascular cast model. It is also a reliable method to demonstrate three-dimensional anatomy of severe congenital heart disease and normal heart in fetus.

Variability of the vertebral artery origin and transverse foramen entrance level - CT angiographic study.

PubMed

Vujmilović, Siniša; Spasojević, Goran; Vujnović, Saša; Malobabić, Slobodan; Vujković, Zoran

2018-04-13

Vertebral artery (VA), the main element of the posterior brain circulation, has many anatomical variations which generally were widely investigated. However, available data vary in wide ranges, reflecting very different sample sizes, lack of data about left-right or sex differences, and about possible ethnic, regionally specific or genetic differences. Certain new findings suggest possible involvement of some environmental factors in VA variations. Accurate anatomical data about VA variations in different regions of the world, including Balkans countries, are still lacking. Therefore we investigated morphological variability of VA origin and its entrance level into cervical transverse foramina in population of Republika Srpska (Bosnia and Herzegovina), including data about the sex and side. Anatomy of VA was investigated in 112 persons (224 arteries) of both sexes (58 males, 54 females; age 19 - 83 years), using 64-slice CT scanner. Origin of VA from subclavian artery (SCA) we found in 95.08% of arteries (52 males, 49 females). Only in one male (0.45 %) left VA and left SCA had an specific origin from aortic arch (AA), which we named as an "common area of origin". All other observed variations in origin were only of left VA, originating from AA in 4.47 % (5 males, 5 females). Left VA Most often (usual) entrance level into transverse foramen we found at C6 (87.5%), followed by C5 (8.93 %), C4 (3.12 %), and in one case at level C7 (0.45 %). Entry levels at C5 both, on right and on the left side, were 3 times more frequent in males than in females. Wide ranges of differences between the data we obtained on a sample in Republika Srpska (Bosnia and Herzegovina) and the data from many other studies require further and wider investigations.

Anatomical variations in the pattern of the right hepatic veins draining the posterior segment of the right lobe of the liver.

PubMed

Shilal, Poonam; Tuli, Anita

2015-03-01

The pattern of drainage in the right posterior lobe of liver varies considerably. The knowledge of this variation is very important while performing various surgeries on the right posterior lobe. A study was conducted to see the variations in the pattern of drainage of posterior segment of the right lobe of liver. The aim was to see the variations of right hepatic vein and small accessory hepatic veins draining the posterior segment, the presence of which led to modifications in drainage of posterior segment. Sixty formalin fixed adult human liver specimens were dissected manually. According to the pattern of drainage of tributaries of right hepatic vein, the right hepatic vein was classified into type I, type II, type III and type IV. According to presence of inferior right hepatic vein, three types of drainage of posterior lobe were seen: Type I, (76.36%) right hepatic vein was large, draining wide area of posterior segment. A small inferior right hepatic vein drained the small area of posterior segment. In Type II, (19.92%) both right hepatic and inferior right hepatic veins were medium sized draining the posteroinferior segment of the right lobe concomitantly. In Type III, (32%) accessory veins, the middle right hepatic vein drained the posterosuperior (VII) as well as the posteroinferior (VI) segment. In one specimen, there were numerous middle right hepatic veins draining the right posterior segment. The knowledge of anatomic relationship of veins draining right lobe, is important in performing right posterior segmentectomy. For safe resection of the liver, the complex anatomy of the distribution of the tributaries of the right hepatic vein and the accessory veins have to be studied prior to any surgery done on liver.

TH-E-17A-06: Anatomical-Adaptive Compressed Sensing (AACS) Reconstruction for Thoracic 4-Dimensional Cone-Beam CT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shieh, C; Kipritidis, J; OBrien, R

2014-06-15

Purpose: The Feldkamp-Davis-Kress (FDK) algorithm currently used for clinical thoracic 4-dimensional (4D) cone-beam CT (CBCT) reconstruction suffers from noise and streaking artifacts due to projection under-sampling. Compressed sensing theory enables reconstruction of under-sampled datasets via total-variation (TV) minimization, but TV-minimization algorithms such as adaptive-steepest-descent-projection-onto-convex-sets (ASD-POCS) often converge slowly and are prone to over-smoothing anatomical details. These disadvantages can be overcome by incorporating general anatomical knowledge via anatomy segmentation. Based on this concept, we have developed an anatomical-adaptive compressed sensing (AACS) algorithm for thoracic 4D-CBCT reconstruction. Methods: AACS is based on the ASD-POCS framework, where each iteration consists of a TV-minimizationmore » step and a data fidelity constraint step. Prior to every AACS iteration, four major thoracic anatomical structures - soft tissue, lungs, bony anatomy, and pulmonary details - were segmented from the updated solution image. Based on the segmentation, an anatomical-adaptive weighting was applied to the TV-minimization step, so that TV-minimization was enhanced at noisy/streaky regions and suppressed at anatomical structures of interest. The image quality and convergence speed of AACS was compared to conventional ASD-POCS using an XCAT digital phantom and a patient scan. Results: For the XCAT phantom, the AACS image represented the ground truth better than the ASD-POCS image, giving a higher structural similarity index (0.93 vs. 0.84) and lower absolute difference (1.1*10{sup 4} vs. 1.4*10{sup 4}). For the patient case, while both algorithms resulted in much less noise and streaking than FDK, the AACS image showed considerably better contrast and sharpness of the vessels, tumor, and fiducial marker than the ASD-POCS image. In addition, AACS converged over 50% faster than ASD-POCS in both cases. Conclusions: The proposed AACS algorithm was shown to reconstruct thoracic 4D-CBCT images more accurately and with faster convergence compared to ASD-POCS. The superior image quality and rapid convergence makes AACS promising for future clinical use.« less

Connectivity-based parcellation of human cingulate cortex and its relation to functional specialization.

PubMed

Beckmann, Matthias; Johansen-Berg, Heidi; Rushworth, Matthew F S

2009-01-28

Whole-brain neuroimaging studies have demonstrated regional variations in function within human cingulate cortex. At the same time, regional variations in cingulate anatomical connections have been found in animal models. It has, however, been difficult to estimate the relationship between connectivity and function throughout the whole cingulate cortex within the human brain. In this study, magnetic resonance diffusion tractography was used to investigate cingulate probabilistic connectivity in the human brain with two approaches. First, an algorithm was used to search for regional variations in the probabilistic connectivity profiles of all cingulate cortex voxels with the whole of the rest of the brain. Nine subregions with distinctive connectivity profiles were identified. It was possible to characterize several distinct areas in the dorsal cingulate sulcal region. Several distinct regions were also found in subgenual and perigenual cortex. Second, the probabilities of connection between cingulate cortex and 11 predefined target regions of interest were calculated. Cingulate voxels with a high probability of connection with the different targets formed separate clusters within cingulate cortex. Distinct connectivity fingerprints characterized the likelihood of connections between the extracingulate target regions and the nine cingulate subregions. Last, a meta-analysis of 171 functional studies reporting cingulate activation was performed. Seven different cognitive conditions were selected and peak activation coordinates were plotted to create maps of functional localization within the cingulate cortex. Regional functional specialization was found to be related to regional differences in probabilistic anatomical connectivity.

Laparoscopic repair of giant paraesophageal hernia: are there factors associated with anatomic recurrence?

PubMed

Antiporda, Michael; Veenstra, Benjamin; Jackson, Chloe; Kandel, Pujan; Daniel Smith, C; Bowers, Steven P

2018-02-01

Repair of giant paraesophageal hernia (PEH) is associated with a favorably high rate of symptom improvement; however, rates of recurrence by objective measures remain high. Herein we analyze our experience with laparoscopic giant PEH repair to determine what factors if any can predict anatomic recurrence. We prospectively collected data on PEH characteristics, variations in operative techniques, and surgeon factors for 595 patients undergoing laparoscopic PEH repair from 2008 to 2015. Upper GI study was performed at 6 months postoperatively and selectively thereafter-any supra-diaphragmatic stomach was considered hiatal hernia recurrence. Exclusion criteria included revisional operation (22.4%), size <5 cm (17.6%), inadequate follow-up (17.8%), and confounding concurrent operations (6.9%). Inclusion criteria were met by 202 patients (31% male, median age 71 years, and median BMI 28.7). At a median follow-up of 6 months (IQR 6-12), overall anatomic recurrence rate was 34.2%. Symptom recurrence rate was 9.9% and revisional operation was required in ten patients (4.9%). Neither patient demographics nor PEH characteristics (size, presence of Cameron erosions, esophagitis, or Barrett's) correlated with anatomic recurrence. Technical factors at operation (mobilized intra-abdominal length of esophagus, Collis gastroplasty, number of anterior/posterior stitches, use of crural buttress, use of pledgeted or mattress sutures, or gastrostomy) were also not correlated with recurrence. Regarding surgeon factors, annual volume of fewer than ten cases per year was associated with increased risk of anatomic failure (54 vs 33%, P = 0.02). Multivariate analysis identified surgeon experience (<10 cases per year) as an independent factor associated with early hiatal hernia recurrence (OR 3.7, 95% CI 1.34-10.9). Laparoscopic repair of giant PEH is associated with high anatomic recurrence rate but excellent symptom control. PEH characteristics and technical operative variables do not appear to significantly affect rates of recurrence. In contrast, surgeon volume does appear to contribute significantly to durability of repair.

An unusual variation in the anatomy of the uncinate process in external dacryocystorhinostomy

PubMed Central

Puri, Nitin

2008-01-01

Variations in the bony components of the nose are often encountered. One such variation was found in a 49-year-old male who had undergone conventional external dacryocystorhinostomy for adult onset nasolacrimal duct blockage. Intraoperatively, a thick bar of bone was seen beneath and parallel to the lacrimal sac fossa after a complete osteotomy had been made. Another osteotomy had to be fashioned in this bone to reach the nasal cavity. Postoperative 3D computed tomographic scan revealed the bone to be an anatomical variation of the uncinate process of the ethmoidal bone which was rather anteriorly placed, much thicker than usual, and attached to the nasal roof. The uncinate process is thin, curved and its anterior edge may frequently overlap some part of the lacrimal fossa. However, to our knowledge, the presence of such a large and thick uncinate process necessitating an additional large osteotomy has not been reported. PMID:18711272

Tunnels and grooves for supraclavicular nerves within the clavicle: review of the literature and clinical impact.

PubMed

Natsis, Konstantinos; Totlis, Trifon; Chorti, Angeliki; Karanassos, Marinos; Didagelos, Matthaios; Lazaridis, Nikolaos

2016-08-01

Perforation of the clavicle by supraclavicular nerves is a common anatomical variation. This variation has been reported in several studies based on post-mortem, surgical and radiologic findings, with an overall frequency between 1 and 6.6 %. The penetrating branch passes either through a bony tunnel or a groove on the superior surface of the bone. Entrapment neuropathy of the perforating branch is a documented clinical entity reported in the literature. The intraosseous course of the supraclavicular nerves makes them vulnerable to injury in case of clavicular fractures or during surgical manipulations of these fractures. Furthermore, this variation should be taken into account during the interpretation of chest and shoulder radiographs. The purpose of the current study is to perform an extended review of the relevant literature, highlighting the clinical impact of this variation, as well as to incorporate our own findings into them.

[INCIDENCE AND SURGICAL IMPORTANCE OF PYRAMIDAL LOBE AND TUBERCLE OF THE THYROID GLAND: A PROSPECTIVE STUDY].

PubMed

Kovacić, Marijan; Kovadcić, Ivan

2015-01-01

The pyramidal lobe and tubercles are common anatomic variations of the thyroid gland, and their frequency is highly represented. While pyramidal lobe requires additional seriousness in identifying and its removal, especially in patients with hyperthyroidism and thyroid cancer, the presence of tubercles is desirable. Tubercle is covered by recurrent laryngeal nerve and directs the surgeon in his search and besides this, serves to facilitate detection of the upper parathyroid glands. In this prospective study we analysed 342 patients who underwent total thyroidectomy in the period from January 2009 to March 2015. We looked at the incidence and anatomic characteristics of pyramidal lobe and tubercles of the thyroid gland. The pyramidal lobe was present in 52.3% of the patients with more frequent central and left placement. Bilateral tubercles were present in 14.9%, while position right-sided phenomenon was represented in 39.5% and 18.5% in lower left (64.3% patients). Their prevalence by gender showed no significant difference (p = 0.59; p = 0.2). Associated presence of pyramidal lobe and tubercles on one or both sides is highly represented in our group of patients (34%), also with no differences by gender (p = 0.29). Length of the pyramidal lobe ranged from 1.3 to 4.7 cm (average 2.3 cm), and the size of tubercles in 36% of patients was over 1 cm. Recurrent laryngeal nerve was only in 1.8% placed laterally of tubercles, and the upper parathyroid gland in 95.4% was located above tubercle. Considering that only 16.5% of our patients did not have any of these anatomical variations, their presence during surgery is the rule, not the exception.

3-Tesla MRI: Beneficial visualization of the meniscofemoral ligaments?

PubMed

Ebrecht, Johanna; Krasny, Andrej; Hartmann, Dinah Maria; Rückbeil, Marcia Viviane; Ritz, Thomas; Prescher, Andreas

2017-10-01

Recent investigations have confirmed an important stabilizing and protective function of the meniscofemoral ligaments (MFLs) to the knee joint and suggest a clinical relevance. Concerning their incidences, however, there have been discrepancies between data acquired from cadaveric studies and MRI data using 0.3- to 1.5-Tesla field strengths probably due to lower resolution. This study aims to investigate whether imaging with 3-Tesla magnetic resonance imaging (3-T MRI) is beneficial in gaining information regarding the ligaments' incidence, length, width and anatomic variation. 3-T MRI images of 448 patients (224 males, 224 females, with, respectively, 32 patients of each sex in the age groups: 0-20, 21-30, 31-40, 41-50, 51-60, 61-70, >70years) were retrospectively reviewed. The influence of the parameters 'sex' and 'age' was determined. Whereas 71% of the patients had at least one MFL, 22% had an anterior MFL (aMFL), 53% had a posterior MFL (pMFL) and five percent had coexisting ligaments. The pMFLs were more likely to be present in female patients (P<0.05) but if so, they were longer in the males (P<0.05). The pMFL was categorized according to its insertion on the medial femoral condyle. 3-T MRI enables an excellent illustration of the anatomic variations of pMFLs. By modifying an anatomic classification for radiological use we measured lengths and widths of the MFLs without any difficulties. Despite its increased resolution, 3-T MRI lends no diagnostic benefit in visualizing the course of the aMFL or filigree coexisting ligaments as compared to MRI at lower field strengths. Copyright © 2017 Elsevier B.V. All rights reserved.

Impact of variant pancreatic arterial anatomy and overlap in regional perfusion on the interpretation of selective arterial calcium stimulation with hepatic venous sampling for preoperative localization of occult insulinoma.

PubMed

Thompson, Scott M; Vella, Adrian; Service, F John; Grant, Clive S; Thompson, Geoffrey B; Andrews, James C

2015-07-01

To determine the impact of variant pancreatic arterial anatomy and overlap in regional perfusion on the interpretation of selective arterial calcium stimulation (SACST) with hepatic venous sampling for preoperative localization of occult insulinoma. An institutional review board-approved retrospective review was undertaken of 42 patients with surgically confirmed, occult insulinoma who underwent SACST from January 1996 to March 2014. Location of the insulinoma was predicted initially based on the biochemical results of SACST alone according to Doppman's criteria. Pancreatic arteriograms were reviewed blinded to the biochemical results and the regional perfusion of each artery assessed. The anatomic and perfusion data were combined with the biochemical results to make a second prediction and compared with the surgical findings. The biochemical results were positive in 1, 2, and 3 arterial distributions in 73.8%, 21.4%, and 4.8% of patients, respectively. The celiac trunk and superior mesenteric artery (SMA) anatomy were aberrant in 38.1% and 35.7% of patients, respectively. Clinically significant variations included dorsal pancreatic artery replaced to SMA (21.4%) and celiac stenosis (4.8%). Significant variation and overlap in regional pancreatic perfusion was observed, particularly for the SMA. Sensitivity for insulinoma localization was 54.8% (diagnostic arteriography), 73.8% (biochemical data), 88.1% (biochemical, anatomic, perfusion data), and 92.8% (arteriographic, biochemical, anatomic, perfusion data). Careful review of the pancreatic arterial anatomy and regional perfusion is critical for correct interpretation of the biochemical results of SACST and improves the sensitivity of localization for occult insulinoma, particularly in the presence of pancreatic arterial variants or overlap in regional perfusion. Copyright © 2015 Elsevier Inc. All rights reserved.

The prevalence and morphology of the corona mortis (Crown of death): A meta-analysis with implications in abdominal wall and pelvic surgery.

PubMed

Sanna, Beatrice; Henry, Brandon Michael; Vikse, Jens; Skinningsrud, Bendik; Pękala, Jakub R; Walocha, Jerzy A; Cirocchi, Roberto; Tomaszewski, Krzysztof A

2018-02-01

Corona mortis is a highly variable vascular connection between the obturator and external iliac or inferior epigastric arteries or veins located behind the superior pubic ramus in the retropubic space (space of Retzius). Due to the significant variation in this collateral circulation, detailed anatomical knowledge of the corona mortis is vital to enhance the prevention of possible iatrogenic errors in hernia repair and other pubic surgical procedures. The aim of our meta-analysis was to provide comprehensive data on the prevalence, anatomical characteristics, and ethnic variations of the corona mortis vessel. An extensive search was conducted through the major electronic databases to identify eligible articles. Data extracted included investigative method, prevalence of the corona mortis vessels among hemi-pelvises (overall, arterial only, venous only, and combined), distance from the corona mortis to pubic symphysis, and assessment of gender, side, laterality, and ethnicity subgroups. A total of 21 studies (n=2184 hemi-pelvises) were included in the meta-analysis. The overall prevalence of the corona mortis in hemi-pelvises is high (49.3%). A venous corona mortis is more prevalent than an arterial corona mortis (41.7% vs. 17.0%). The corona mortis is more common in Asia (59.3%) than in Europe (42.8%) and North America (44.3%). As a corona mortis is present in an about half of all hemi-pelvises, it is important to consider the possibilities of its presence when undertaking surgical procedures and plan accordingly to avoid injuries. All surgeons operating in the retropubic region should have a thorough understanding of the anatomical characteristics and surgical implications of a corona mortis. Copyright © 2017 Elsevier Ltd. All rights reserved.

An anatomical study of wormian bones from the eastern part of India: is genetic influence a primary determinant of their morphogenesis?

PubMed

Ghosh, Sanjib Kumar; Biswas, Sudipa; Sharma, Suranjali; Chakraborty, Soumya

2017-06-01

Over the years a number of investigators have analysed the morphology of wormian bones in different population groups across the world. There have been significant variations between findings reported in these studies, and this has prompted researchers to focus on the influence of genetic factors on the morphology of these bones. In the light of the above observation, we considered it justified to conduct anatomical studies on wormian bones in different population groups; hence, we undertook the present study to look into the morphological details of these bones among a population in the eastern part of India. We observed a total of 120 adult dry human skulls of unknown age and sex, and noted the anatomical details of wormian bones when present. It was observed that wormian bones were present in 45 % of skulls, and that 30 % of skulls had more than one wormian bone. We also found that 2.5 % of the skulls had ten or more wormian bones, which is considered as pathognomonic. Maximum incidence (53.33 %) was observed at the lambdoid suture and minimum incidence at the bregma and metopic suture (0.61 % in each case). We noted a high incidence (21.21 %) of Inca bone/lambdoid ossicle, and bilaterally symmetrical wormian bones were present in 12.5 % study skulls. There were statistically significant (P < 0.05) variations between the findings of the present study and values reported in previous studies conducted in other regions of India and different parts of the world. Our observations favour the view that genetic influence primarily determines the morphology of wormian bones.

Depressive Symptoms, Anatomical Region, and Clinical Outcomes for Patients Seeking Outpatient Physical Therapy for Musculoskeletal Pain

PubMed Central

Coronado, Rogelio A.; Beneciuk, Jason M.; Valencia, Carolina; Werneke, Mark W.; Hart, Dennis L.

2011-01-01

Background Clinical guidelines advocate the routine identification of depressive symptoms for patients with pain in the lumbar or cervical spine, but not for other anatomical regions. Objective The purpose of this study was to investigate the prevalence and impact of depressive symptoms for patients with musculoskeletal pain across different anatomical regions. Design This was a prospective, associational study. Methods Demographic, clinical, depressive symptom (Symptom Checklist 90–Revised), and outcome data were collected by self-report from a convenience sample of 8,304 patients. Frequency of severe depressive symptoms was assessed by chi-square analysis for demographic and clinical variables. An analysis of variance examined the influence of depressive symptoms and anatomical region on intake pain intensity and functional status. Separate hierarchical multiple regression models by anatomical region examined the influence of depressive symptoms on clinical outcomes. Results Prevalence of severe depression was higher in women, in industrial and pain clinics, and in patients who reported chronic pain or prior surgery. Lower prevalence rates were found in patients older than 65 years and those who had upper- or lower-extremity pain. Depressive symptoms had a moderate to large effect on pain ratings (Cohen d=0.55–0.87) and a small to large effect on functional status (Cohen d=0.28–0.95). In multivariate analysis, depressive symptoms contributed additional variance to pain intensity and functional status for all anatomical locations, except for discharge values for the cervical region. Conclusions Rates of depressive symptoms varied slightly based on anatomical region of musculoskeletal pain. Depressive symptoms had a consistent detrimental influence on outcomes, except on discharge scores for the cervical anatomical region. Expanding screening recommendations for depressive symptoms to include more anatomical regions may be indicated in physical therapy settings. PMID:21233305

Drivers of international variation in prevalence of disabling low back pain: Findings from the Cultural and Psychosocial Influences on Disability study.

PubMed

Coggon, D; Ntani, G; Palmer, K T; Felli, V E; Harari, F; Quintana, L A; Felknor, S A; Rojas, M; Cattrell, A; Vargas-Prada, S; Bonzini, M; Solidaki, E; Merisalu, E; Habib, R R; Sadeghian, F; Kadir, M M; Warnakulasuriya, S S P; Matsudaira, K; Nyantumbu-Mkhize, B; Kelsall, H L; Harcombe, H

2018-06-08

Wide international variation in the prevalence of disabling low back pain (LBP) among working populations is not explained by known risk factors. It would be useful to know whether the drivers of this variation are specific to the spine or factors that predispose to musculoskeletal pain more generally. Baseline information about musculoskeletal pain and risk factors was elicited from 11 710 participants aged 20-59 years, who were sampled from 45 occupational groups in 18 countries. Wider propensity to pain was characterized by the number of anatomical sites outside the low back that had been painful in the 12 months before baseline ('pain propensity index'). After a mean interval of 14 months, 9055 participants (77.3%) provided follow-up data on disabling LBP in the past month. Baseline risk factors for disabling LBP at follow-up were assessed by random intercept Poisson regression. After allowance for other known and suspected risk factors, pain propensity showed the strongest association with disabling LBP (prevalence rate ratios up to 2.6, 95% CI: 2.2-3.1; population attributable fraction 39.8%). Across the 45 occupational groups, the prevalence of disabling LBP varied sevenfold (much more than within-country differences between nurses and office workers), and correlated with mean pain propensity index (r = 0.58). Within our study, major international variation in the prevalence of disabling LBP appeared to be driven largely by factors predisposing to musculoskeletal pain at multiple anatomical sites rather than by risk factors specific to the spine. Our findings indicate that differences in general propensity to musculoskeletal pain are a major driver of large international variation in the prevalence of disabling low back pain among people of working age. © 2018 The Authors. European Journal of Pain published by John Wiley & Sons Ltd on behalf of European Pain Federation - EFIC®.

Round and Oval Window Anatomic Variability: Its Implication for the Vibroplasty Technique.

PubMed

Mancheño, Marta; Aristegui, Miguel; Sañudo, Jose Ramon

2017-06-01

The objective of this study is to evaluate the anatomical variability of round and oval window regions and its relationship with their closest structures, to determine its implication on the fitting and stabilization of the middle ear implant Vibrant Soundbridge. Variations of the anatomy of round and oval window regions were assessed in a total of 85 human dissected temporal bones. Afterward, we evaluated the adaptation and subsequent stabilization of the floating mass transducer (FMT) of the Vibrant Soundbridge in 67 cases in round window (RW) and in 22 cases in oval window (OW), and the influence that the variability of the different anatomical features examined had on this stabilization. We also assessed access and surgeon's view of the RW niche through the facial recess approach. Stabilization of the FMT in the RW was achieved in 53 (79%) of the 67 cases; we found that the less favorable anatomical conditions for stabilization were: membrane smaller than 1.5 mm, presence of a high jugular bulb and a narrow or very narrow RW niche. Frequently, two or more of these conditions happened simultaneously. In seven cases (22%) access to the RW through facial recess approach did not allow positioning the FMT in place. OW stabilization succeeded in 18 (82%) of the 22 cases. Round and oval window vibroplasty are difficult surgical techniques. To place the FMT directly on the OW may be easier as we do not have to drill the niche. In both regions there are some anatomical conditions that hinder fitting the FMT and even make it impossible. Once fitted, the main problem is to achieve good stabilization of the device.

Fabrication and assessment of 3D printed anatomical models of the lower limb for anatomical teaching and femoral vessel access training in medicine.

PubMed

O'Reilly, Michael K; Reese, Sven; Herlihy, Therese; Geoghegan, Tony; Cantwell, Colin P; Feeney, Robin N M; Jones, James F X

2016-01-01

For centuries, cadaveric dissection has been the touchstone of anatomy education. It offers a medical student intimate access to his or her first patient. In contrast to idealized artisan anatomical models, it presents the natural variation of anatomy in fine detail. However, a new teaching construct has appeared recently in which artificial cadavers are manufactured through three-dimensional (3D) printing of patient specific radiological data sets. In this article, a simple powder based printer is made more versatile to manufacture hard bones, silicone muscles and perfusable blood vessels. The approach involves blending modern approaches (3D printing) with more ancient ones (casting and lost-wax techniques). These anatomically accurate models can augment the approach to anatomy teaching from dissection to synthesis of 3D-printed parts held together with embedded rare earth magnets. Vascular simulation is possible through application of pumps and artificial blood. The resulting arteries and veins can be cannulated and imaged with Doppler ultrasound. In some respects, 3D-printed anatomy is superior to older teaching methods because the parts are cheap, scalable, they can cover the entire age span, they can be both dissected and reassembled and the data files can be printed anywhere in the world and mass produced. Anatomical diversity can be collated as a digital repository and reprinted rather than waiting for the rare variant to appear in the dissection room. It is predicted that 3D printing will revolutionize anatomy when poly-material printing is perfected in the early 21st century. © 2015 American Association of Anatomists.

ANATOMIC VARIATIONS OF HEPATIC ARTERY: A STUDY IN 479 LIVER TRANSPLANTATIONS.

PubMed

Fonseca-Neto, Olival Cirilo Lucena da; Lima, Heloise Caroline de Souza; Rabelo, Priscylla; Melo, Paulo Sérgio Vieira de; Amorim, Américo Gusmão; Lacerda, Cláudio Moura

2017-01-01

The incidence of anatomic variations of hepatic artery ranges from 20-50% in different series. Variations are especially important in the context of liver orthotopic transplantation, since, besides being an ideal opportunity for surgical anatomical study, their precise identification is crucial to the success of the procedure. To identify the anatomical variations in the hepatic arterial system in hepatic transplantation. 479 medical records of transplanted adult patients in the 13-year period were retrospectively analyzed, and collected data on hepatic arterial anatomy of the deceased donor. It was identified normal hepatic arterial anatomy in 416 donors (86.84%). The other 63 patients (13.15%) showed some variation. According to the Michels classification, the most frequently observed abnormalities were: right hepatic artery branch of superior mesenteric artery (Type III, n=27, 5.63%); left hepatic artery branch of the left gastric artery (Type II, n=13, 2.71%); right hepatic artery arising from the superior mesenteric artery associated with the left hepatic artery arising from the left gastric artery (Type IV, n=4, 0.83%). Similarly, in relation to Hiatt classification, the most prevalent changes were: right hepatic accessory artery or substitute of the superior mesenteric artery (Type III, n=28, 6.05%)), followed by liver ancillary left artery or replacement of gastric artery left (Type II, n=16, 3.34. Fourteen donors (2.92%) showed no anatomical abnormalities defined in classifications, the highest frequency being hepatomesenteric trunk identified in five (01.04%). Detailed knowledge of the variations of hepatic arterial anatomy is of utmost importance to surgeons who perform approaches in this area, particularly in liver transplantation, since their identification and proper management are critical to the success of the procedure. A incidência das variações anatômicas da artéria hepática varia de 20-50% em diferentes casuísticas. Elas são especialmente importantes no contexto do transplante ortotópico hepático, visto que, além de representar oportunidade ideal para seu estudo anatômico cirúrgico, a sua precisa identificação é determinante para o sucesso do procedimento. Identificar as variações anatômicas no sistema arterial hepático em transplantes hepáticos. Foram analisados retrospectivamente, no período de 13 anos, 479 prontuários de pacientes adultos transplantados, sendo coletados dados referentes à anatomia arterial hepática do doador falecido. Identificou-se anatomia arterial hepática normal em 416 doadores (86,84%). Os outros 63 indivíduos (13,15%) apresentaram alguma variação. De acordo com a classificação de Michels, as anomalias mais frequentes foram: artéria hepática direita ramo da artéria mesentérica superior (Tipo III, n=27, 5,63%); artéria hepática esquerda ramo da artéria gástrica esquerda (Tipo II, n=13, 2,71%); artéria hepática direita ramo da artéria mesentérica superior associada à artéria hepática esquerda ramo da artéria gástrica esquerda (Tipo IV, n=4, 0,83%). Do mesmo modo, em relação à Classificação de Hiatt, as variações mais prevalentes foram: artéria hepática direita acessória ou substituta da artéria mesentérica superior (Tipo III, n=28, 6,05%), seguida da artéria hepática esquerda acessória ou substituta da artéria gástrica esquerda (Tipo II, n=16, 3,34%). Quatorze pessoas (2,92%) apresentaram alterações anatômicas sem classificação definida, sendo a de maior frequência o tronco hepatomesentérico, identificado em cinco (1,04%). O conhecimento detalhado das variações da anatomia arterial hepática é de grande importância aos cirurgiões que realizam abordagens nessa região, em especial no transplante hepático, visto que sua identificação e correto manejo são fundamentais para o êxito do procedimento.

Networks of myelin covariance.

PubMed

Melie-Garcia, Lester; Slater, David; Ruef, Anne; Sanabria-Diaz, Gretel; Preisig, Martin; Kherif, Ferath; Draganski, Bogdan; Lutti, Antoine

2018-04-01

Networks of anatomical covariance have been widely used to study connectivity patterns in both normal and pathological brains based on the concurrent changes of morphometric measures (i.e., cortical thickness) between brain structures across subjects (Evans, ). However, the existence of networks of microstructural changes within brain tissue has been largely unexplored so far. In this article, we studied in vivo the concurrent myelination processes among brain anatomical structures that gathered together emerge to form nonrandom networks. We name these "networks of myelin covariance" (Myelin-Nets). The Myelin-Nets were built from quantitative Magnetization Transfer data-an in-vivo magnetic resonance imaging (MRI) marker of myelin content. The synchronicity of the variations in myelin content between anatomical regions was measured by computing the Pearson's correlation coefficient. We were especially interested in elucidating the effect of age on the topological organization of the Myelin-Nets. We therefore selected two age groups: Young-Age (20-31 years old) and Old-Age (60-71 years old) and a pool of participants from 48 to 87 years old for a Myelin-Nets aging trajectory study. We found that the topological organization of the Myelin-Nets is strongly shaped by aging processes. The global myelin correlation strength, between homologous regions and locally in different brain lobes, showed a significant dependence on age. Interestingly, we also showed that the aging process modulates the resilience of the Myelin-Nets to damage of principal network structures. In summary, this work sheds light on the organizational principles driving myelination and myelin degeneration in brain gray matter and how such patterns are modulated by aging. © 2017 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

Vesalius, Röntgen and the origins of Modern Anatomy.

PubMed

Thomas, Adrian M K

2016-06-01

The discovery of X-rays in 1895 by Wilhelm Conrad Röntgen transformed our understanding of both the physical world and our understanding of ourselves. Traditional anatomy as shown by Andreas Vesalius was learnt from dissection of the supine deceased body. Radiology showed anatomy in the living in a manner previously not possible, and has transformed our anatomical understanding, particularly of human growth and variation.

Double-outlet left ventricle with L-malposition of the great arteries and subpulmonary ventricular septal defect.

PubMed

Vukomanovic, Vladislav; Prijic, Sergej; Bjelakovic, Bojko

2013-02-01

Double-outlet left ventricle is a very rare congenital cardiac anomaly with various anatomic types. This report describes an infant with the aorta anterior and to the left of the pulmonary trunk, a subpulmonary ventricular septal defect, and pulmonary artery stenosis. This variation has not been described to date in patients with a double-outlet left ventricle.

Anomalous origin of the right colic artery from the right gastroepiploic artery during complete mesocolic excision: a rare case report

PubMed Central

Zoulamoglou, Menelaos; Theodoropoulos, Panagiotis; Kakaviatos, Dimosthenis; Kaklamanos, Ioannis; Flessas, Ioannis; Piperos, Theodoros; Varlatzidou, Alexandra; Troupis, Theodoros; Mariolis-Sapsakos, Theodoros

2017-01-01

Abstract Complete mesocolic excision (CME) is a standardized surgical procedure for colonic cancer that requires ample knowledge of the anatomical patterns of the colic arteries. Variations of the colic vessels encumber both surgical and endovascular techniques. In the presented case below, the right colic artery was incidentally detected emerging from the right gastroepiploic artery, during CME. Surgeons should be always aware of this variation in order to perform safe abdominal surgeries and sufficient resection of the regional lymph nodes with a view to minimizing the probability of recurrence of disease when encountering colonic cancer. PMID:29218209

Developmental effects of antiepileptic drugs and the need for improved regulations

PubMed Central

Loring, David W.

2016-01-01

Antiepileptic drugs (AEDs) are among the most common teratogenic drugs prescribed to women of childbearing age. AEDs can induce both anatomical (malformations) and behavioral (cognitive/behavioral deficits) teratogenicity. Only in the last decade have we begun to truly discriminate differential AED developmental effects. Fetal valproate exposure carries a special risk for both anatomical and behavioral teratogenic abnormalities, but the mechanisms and reasons for individual variability are unknown. Intermediate anatomical risks exist for phenobarbital and topiramate. Several AEDs (e.g., lamotrigine and levetiracetam) appear to possess low risks for both anatomical and behavioral teratogenesis. Despite advances in the past decade, our knowledge of the teratogenic risks for most AEDs and the underlying mechanisms remain inadequate. Further, the long-term effects of AEDs in neonates and older children remain uncertain. The pace of progress is slow given the lifelong consequences of diminished developmental outcomes, exposing children unnecessarily to potential adverse effects. It is imperative that new approaches be employed to determine risks more expediently. Our recommendations include a national reporting system for congenital malformations, federal funding of the North American AED Pregnancy Registry, routine meta-analyses of cohort studies to detect teratogenic signals, monitoring of AED prescription practices for women, routine preclinical testing of all new AEDs for neurodevelopmental effects, more specific Food and Drug Administration requirements to establish differential AED cognitive effects in children, and improved funding of basic and clinical research to fully delineate risks and underlying mechanisms for AED-induced anatomical and behavioral teratogenesis. PMID:26519545

Facial reconstruction – anatomical art or artistic anatomy?

PubMed Central

Wilkinson, Caroline

2010-01-01

Facial reconstruction is employed in the context of forensic investigation and for creating three-dimensional portraits of people from the past, from ancient Egyptian mummies and bog bodies to digital animations of J. S. Bach. This paper considers a facial reconstruction method (commonly known as the Manchester method) associated with the depiction and identification of the deceased from skeletal remains. Issues of artistic licence and scientific rigour, in relation to soft tissue reconstruction, anatomical variation and skeletal assessment, are discussed. The need for artistic interpretation is greatest where only skeletal material is available, particularly for the morphology of the ears and mouth, and with the skin for an ageing adult. The greatest accuracy is possible when information is available from preserved soft tissue, from a portrait, or from a pathological condition or healed injury. PMID:20447245

Molecular relationships between closely related strains and species of nematodes

NASA Technical Reports Server (NTRS)

Butler, M. H.; Wall, S. M.; Luehrsen, K. R.; Fox, G. E.; Hecht, R. M.

1981-01-01

Electrophoretic comparisons have been made for 24 enzymes in the Bergerac and Bristol strains of Caenorhabditis elegans and the related species, Caenorhabditis briggsae. No variation was detected between the two strains of C. elegans. In contrast, the two species, C. elegans and C. briggsae exhibited electrophoretic differences in 22 of 24 enzymes. A consensus 5S rRNA sequence was determined for C. elegans and found to be identical to that from C. briggsae. By analogy with other species with relatively well established fossil records it can be inferred that the time of divergence between the two nematode species is probably in the tens of millions of years. The limited anatomical evolution during a time period in which proteins undergo extensive changes supports the hypothesis that anatomical evolution is not dependent on overall protein changes.

A mandibular third molar with three mesial roots: a case report.

PubMed

Plotino, Gianluca

2008-02-01

Although its most common configuration is 2 roots and 3 root canals, mandibular molars might have many different combinations. A case of unusual root canal morphology is presented to demonstrate anatomic variations in mandibular molars. Endodontic therapy was performed in a mandibular third molar with 3 separate mesial roots. The appearance of the pulp chamber floor revealed 4 separate canal orifices. Radiographically the 4 root canals ended in their own distinct foramen. Many reports deal with 3 orifices or 3 independent canals in the mesial root, but none described 3 mesial canals in 3 separate mesial roots, indicating a rare anatomic configuration. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure.

Neocortical malformation as consequence of nonadaptive regulation of neuronogenetic sequence

NASA Technical Reports Server (NTRS)

Caviness, V. S. Jr; Takahashi, T.; Nowakowski, R. S.

2000-01-01

Variations in the structure of the neocortex induced by single gene mutations may be extreme or subtle. They differ from variations in neocortical structure encountered across and within species in that these "normal" structural variations are adaptive (both structurally and behaviorally), whereas those associated with disorders of development are not. Here we propose that they also differ in principle in that they represent disruptions of molecular mechanisms that are not normally regulatory to variations in the histogenetic sequence. We propose an algorithm for the operation of the neuronogenetic sequence in relation to the overall neocortical histogenetic sequence and highlight the restriction point of the G1 phase of the cell cycle as the master regulatory control point for normal coordinate structural variation across species and importantly within species. From considerations based on the anatomic evidence from neocortical malformation in humans, we illustrate in principle how this overall sequence appears to be disrupted by molecular biological linkages operating principally outside the control mechanisms responsible for the normal structural variation of the neocortex. MRDD Research Reviews 6:22-33, 2000. Copyright 2000 Wiley-Liss, Inc.

Variations in the ceramide profile in different seasons and regions of the body contribute to stratum corneum functions.

PubMed

Ishikawa, Junko; Shimotoyodome, Yoshie; Ito, Shotaro; Miyauchi, Yuki; Fujimura, Tsutomu; Kitahara, Takashi; Hase, Tadashi

2013-03-01

The objective of this study was to clarify variations of the ceramide (CER) profile in human stratum corneum (SC) in different seasons and in different regions of the body and to estimate the contributions of CERs to the SC barrier and water-holding functions. Based on the information that there are great variations of SC functions among body sites, we compared the CER profiles obtained from ten different anatomical sites in healthy Japanese males in four seasons. Not only the physiological parameters of skin but also the CER profile showed body region and seasonal variations. The total CER level, the CER composition and the C34-CER[NS] species displayed strong correlations with the values of transepidermal water loss and capacitance throughout the body. Especially in the cheek, a strong correlation between the capacitance and the CER profile was observed. There were seasonal variations of the CER profile in the lip, upper arm and palm. Our results indicate that regional and seasonal variations of the CER profile may contribute to SC functions.

Morphological and molecular variation in Mitchella undulata, with special reference to the systematic treatment of the dwarf form from Yakushima.

PubMed

Yokoyama, Jun; Fukuda, Tatsuya; Tsukaya, Hirokazu

2003-08-01

Morphological and molecular variation in Mitchella undulata Siebold et Zucc. was examined to evaluate the genetic basis for recognizing the dwarf variety, M. undulata var. minor Masamune. Considerable variation in leaf size in M. undulata, but no obvious morphological discontinuities, were found between the normal and dwarf varieties. Instead, a weak cline running from the Pacific Ocean to the Sea of Japan was found. Anatomical observations of leaf blades revealed that the large variation in leaf size can be attributed to variation in the number of leaf cells and not to differences in cell size. A molecular analysis based on sequences of rDNA internal transcribed spacer regions indicated that there were two major genotypes in M. undulata with minor variation in haplotypes resulting from additional substitutions or putative recombination. The dwarf form from Yakushima was neither genetically uniform nor apparently differentiated from other populations. From these results, we conclude that the dwarf form of M. undulata should be treated at the rank of forma.

Anatomical Distribution of Lipids in Human Brain Cortex by Imaging Mass Spectrometry

NASA Astrophysics Data System (ADS)

Veloso, Antonio; Astigarraga, Egoitz; Barreda-Gómez, Gabriel; Manuel, Iván; Ferrer, Isidro; Teresa Giralt, María; Ochoa, Begoña; Fresnedo, Olatz; Rodríguez-Puertas, Rafael; Fernández, José A.

2011-02-01

Molecular mass images of tissues will be biased if differences in the physicochemical properties of the microenvironment affect the intensity of the spectra. To address this issue, we have performed—by means of MALDI-TOF mass spectrometry—imaging on slices and lipidomic analysis in extracts of frontal cortex, both from the same postmortem tissue samples of human brain. An external calibration was used to achieve a mass accuracy of 10 ppm (1 σ) in the spectra of the extracts, although the final assignment was based on a comparison with previously reported species. The spectra recorded directly from tissue slices (imaging) show excellent s/n ratios, almost comparable to those obtained from the extracts. In addition, they retain the information about the anatomical distribution of the molecular species present in autopsied frozen tissue. Further comparison between the spectra from lipid extracts devoid of proteins and those recorded directly from the tissue unambiguously show that the differences in lipid composition between gray and white matter observed in the mass images are not an artifact due to microenvironmental influences of each anatomical area on the signal intensity, but real variations in the lipid composition.

Radiological features for the approach in trans-sphenoidal pituitary surgery.

PubMed

Twigg, Victoria; Carr, Simon D; Balakumar, Ramkishan; Sinha, Saurabh; Mirza, Showkat

2017-08-01

In order to perform trans-sphenoidal endoscopic pituitary surgery safely and efficiently it is important to identify anatomical and pituitary disease features on the pre-operative CT and MRI scans; thereby minimising the risk to surrounding structures and optimising outcomes. We aim to create a checklist to streamline pre-operative planning. We retrospectively reviewed pre-operative CT and MRI scans of 100 adults undergoing trans-sphenoidal endoscopic pituitary surgery. Radiological findings and their incidence included deviated nasal septum (62%), concha bullosa (32%), bony dehiscence of the carotid arteries (18%), sphenoid septation overlying the internal carotid artery (24% at the sella) and low lying CSF (32%). The mean distance of the sphenoid ostium to the skull base was 10 mm (range 2.7-17.6 mm). We also describe the 'teddy bear' sign which when present on an axial CT indicates the carotid arteries will be identifiable intra-operatively. There are significant variations in the anatomical and pituitary disease features between patients. We describe a number of features on pre-operative scans and have devised a checklist including a new 'teddy bear' sign to aid the surgeon in the anatomical assessment of patients undergoing trans-sphenoidal pituitary surgery.

[Modification of the retrolabyrinthine approach with hearing preservation in CPA tumors].

PubMed

Schipper, J; Lohnstein, P; Stummer, W; Knapp, F; Turowski, B; Klenzner, T

2010-02-01

In an anatomical study including a CT scan of the cadaver sections by means of a virtual model analysis the option of a modified retrolabyrinthine passage to the cerebellopontine angle (CPA) preserving the Saccus endolymphaticus and the upper petrosus sinus was analysed. Due to the individual anatomical variations of the petrosus bone the results showed several limitations with regard to the retrolabyrintine passage to the CPA. The smallest distance between the dura of the posterior fossa and the posterior semicircular canal measured in a high resolution CT was of particular importance as to how much room was available for the surgical manipulation in the retrolabyrinthine space. As the back side angle to the petrosus bone is much flatter in a translabyrinthine approach than in a retrosigmoidal approach the internal auditory canal needed to be controlled by using a 30 degree endoscope. In five patients the translabyrinthine approach was modified by temporarily preserving the labyrinth in an effort to remove the CPA tumors. Based on our clinical experience and on the findings of the anatomical and radiological studies we eventually removed the CPA tumors type B2 or C3 in three patients preserving hearing by using a modified retrolabyrinthine approach.

An anatomically comprehensive atlas of the adult human brain transcriptome

PubMed Central

Guillozet-Bongaarts, Angela L.; Shen, Elaine H.; Ng, Lydia; Miller, Jeremy A.; van de Lagemaat, Louie N.; Smith, Kimberly A.; Ebbert, Amanda; Riley, Zackery L.; Abajian, Chris; Beckmann, Christian F.; Bernard, Amy; Bertagnolli, Darren; Boe, Andrew F.; Cartagena, Preston M.; Chakravarty, M. Mallar; Chapin, Mike; Chong, Jimmy; Dalley, Rachel A.; David Daly, Barry; Dang, Chinh; Datta, Suvro; Dee, Nick; Dolbeare, Tim A.; Faber, Vance; Feng, David; Fowler, David R.; Goldy, Jeff; Gregor, Benjamin W.; Haradon, Zeb; Haynor, David R.; Hohmann, John G.; Horvath, Steve; Howard, Robert E.; Jeromin, Andreas; Jochim, Jayson M.; Kinnunen, Marty; Lau, Christopher; Lazarz, Evan T.; Lee, Changkyu; Lemon, Tracy A.; Li, Ling; Li, Yang; Morris, John A.; Overly, Caroline C.; Parker, Patrick D.; Parry, Sheana E.; Reding, Melissa; Royall, Joshua J.; Schulkin, Jay; Sequeira, Pedro Adolfo; Slaughterbeck, Clifford R.; Smith, Simon C.; Sodt, Andy J.; Sunkin, Susan M.; Swanson, Beryl E.; Vawter, Marquis P.; Williams, Derric; Wohnoutka, Paul; Zielke, H. Ronald; Geschwind, Daniel H.; Hof, Patrick R.; Smith, Stephen M.; Koch, Christof; Grant, Seth G. N.; Jones, Allan R.

2014-01-01

Neuroanatomically precise, genome-wide maps of transcript distributions are critical resources to complement genomic sequence data and to correlate functional and genetic brain architecture. Here we describe the generation and analysis of a transcriptional atlas of the adult human brain, comprising extensive histological analysis and comprehensive microarray profiling of ~900 neuroanatomically precise subdivisions in two individuals. Transcriptional regulation varies enormously by anatomical location, with different regions and their constituent cell types displaying robust molecular signatures that are highly conserved between individuals. Analysis of differential gene expression and gene co-expression relationships demonstrates that brain-wide variation strongly reflects the distributions of major cell classes such as neurons, oligodendrocytes, astrocytes and microglia. Local neighbourhood relationships between fine anatomical subdivisions are associated with discrete neuronal subtypes and genes involved with synaptic transmission. The neocortex displays a relatively homogeneous transcriptional pattern, but with distinct features associated selectively with primary sensorimotor cortices and with enriched frontal lobe expression. Notably, the spatial topography of the neocortex is strongly reflected in its molecular topography— the closer two cortical regions, the more similar their transcriptomes. This freely accessible online data resource forms a high-resolution transcriptional baseline for neurogenetic studies of normal and abnormal human brain function. PMID:22996553

Effective Connectivity Modeling for fMRI: Six Issues and Possible Solutions Using Linear Dynamic Systems

PubMed Central

Smith, Jason F.; Pillai, Ajay; Chen, Kewei; Horwitz, Barry

2012-01-01

Analysis of directionally specific or causal interactions between regions in functional magnetic resonance imaging (fMRI) data has proliferated. Here we identify six issues with existing effective connectivity methods that need to be addressed. The issues are discussed within the framework of linear dynamic systems for fMRI (LDSf). The first concerns the use of deterministic models to identify inter-regional effective connectivity. We show that deterministic dynamics are incapable of identifying the trial-to-trial variability typically investigated as the marker of connectivity while stochastic models can capture this variability. The second concerns the simplistic (constant) connectivity modeled by most methods. Connectivity parameters of the LDSf model can vary at the same timescale as the input data. Further, extending LDSf to mixtures of multiple models provides more robust connectivity variation. The third concerns the correct identification of the network itself including the number and anatomical origin of the network nodes. Augmentation of the LDSf state space can identify additional nodes of a network. The fourth concerns the locus of the signal used as a “node” in a network. A novel extension LDSf incorporating sparse canonical correlations can select most relevant voxels from an anatomically defined region based on connectivity. The fifth concerns connection interpretation. Individual parameter differences have received most attention. We present alternative network descriptors of connectivity changes which consider the whole network. The sixth concerns the temporal resolution of fMRI data relative to the timescale of the inter-regional interactions in the brain. LDSf includes an “instantaneous” connection term to capture connectivity occurring at timescales faster than the data resolution. The LDS framework can also be extended to statistically combine fMRI and EEG data. The LDSf framework is a promising foundation for effective connectivity analysis. PMID:22279430

Radiographic evaluation of anatomical variables in maxilla and mandible in relation to dental implant placement.

PubMed

Chandra, Poornima; Govindaraju, Poornima; Chowdhary, Ramesh

2016-01-01

Oral rehabilitation using implants is rapidly replacing tooth supported prostheses. The success of implants is largely dependent on the quality and quantity of alveolar bone. In this study, we assessed the location of limiting anatomical structures and the amount of alveolar bone available for implant placement. Six hundred digital panoramic radiographs (300 males and 300 females) of dentate patients aged between 15-60 years were selected from the archives. The radiographs were subdivided into 3 groups with age interval of 15 years. Then the location of mental foramen, anterior loop, mandibular canal and maxillary sinus was determined. The amount of bone available was measured in both maxilla and mandible in the premolar and molar regions. The mental foramen was most commonly located at the apex of the second premolar in both the genders. The anterior loop was more readily visible in the younger age group. The amount of bone available in the premolar and molar region of the mandible is nearly the same, while more bone is available in the premolar region of the maxilla. The location and morphology of anatomical structures of the jaws vary not only in different populations but also within the same population. The amount of bone available also showed variations in the same population and in the same individual on the right and left sides. The limiting anatomical structures govern the amount of bone available for possible implant placement.

Possible paleohydrologic and paleoclimatic effects on hominin migration and occupation of the Levantine Middle Paleolithic.

PubMed

Frumkin, Amos; Bar-Yosef, Ofer; Schwarcz, Henry P

2011-04-01

This paper explores the impact of major glacial/interglacial paleohydrologic variations in the Middle-Paleolithic Levant on hominin migration and occupation. The climatic reconstruction is based primarily on the most straight-forward paleohydrologic records recently published. These terrestrial proxies convey direct paleoenvironmental signals of effective precipitation and aquifer recharge. The two main proxies are temporal changes of terminal lake levels in the Dead Sea basin and periods of deposition or non-deposition of speleothems. Other records, such as stable isotopes, if interpreted correctly, correspond well with these two direct proxies. All the records consistently indicate that the last two glacial periods in the central Levant were generally wet and cool, while the last two interglacials were dry and warm, so more water was available for the ecosystem and thus hominins during glacial periods than during interglacials. Some proxies indicate that the higher precipitation/evaporation ratio during glacial periods involved higher precipitation rather than only reduced evaporation. Beyond the general mean glacial/interglacial climate suggested here, variations occurred at all temporal scales throughout glacial or interglacial periods. In the Sahara-Negev arid barrier, moister conditions occurred during Marine Isotope Stage (MIS) 6a-5e, when Anatomically Modern Humans apparently migrated out of Africa. We suggest that this migration, as well as the later Neanderthal expansion from Southeast Europe or the Anatolian plateau into the Levant during early MIS 4, could be facilitated by the observed major climatic variations. Copyright © 2010 Elsevier Ltd. All rights reserved.

Figures of merit for detectors in digital radiography. II. Finite number of secondaries and structured backgrounds.

PubMed

Pineda, Angel R; Barrett, Harrison H

2004-02-01

The current paradigm for evaluating detectors in digital radiography relies on Fourier methods. Fourier methods rely on a shift-invariant and statistically stationary description of the imaging system. The theoretical justification for the use of Fourier methods is based on a uniform background fluence and an infinite detector. In practice, the background fluence is not uniform and detector size is finite. We study the effect of stochastic blurring and structured backgrounds on the correlation between Fourier-based figures of merit and Hotelling detectability. A stochastic model of the blurring leads to behavior similar to what is observed by adding electronic noise to the deterministic blurring model. Background structure does away with the shift invariance. Anatomical variation makes the covariance matrix of the data less amenable to Fourier methods by introducing long-range correlations. It is desirable to have figures of merit that can account for all the sources of variation, some of which are not stationary. For such cases, we show that the commonly used figures of merit based on the discrete Fourier transform can provide an inaccurate estimate of Hotelling detectability.

Effects of Regularisation Priors and Anatomical Partial Volume Correction on Dynamic PET Data

NASA Astrophysics Data System (ADS)

Caldeira, Liliana L.; Silva, Nuno da; Scheins, Jürgen J.; Gaens, Michaela E.; Shah, N. Jon

2015-08-01

Dynamic PET provides temporal information about the tracer uptake. However, each PET frame has usually low statistics, resulting in noisy images. Furthermore, PET images suffer from partial volume effects. The goal of this study is to understand the effects of prior regularisation on dynamic PET data and subsequent anatomical partial volume correction. The Median Root Prior (MRP) regularisation method was used in this work during reconstruction. The quantification and noise in image-domain and time-domain (time-activity curves) as well as the impact on parametric images is assessed and compared with Ordinary Poisson Ordered Subset Expectation Maximisation (OP-OSEM) reconstruction with and without Gaussian filter. This study shows the improvement in PET images and time-activity curves (TAC) in terms of noise as well as in the parametric images when using prior regularisation in dynamic PET data. Anatomical partial volume correction improves the TAC and consequently, parametric images. Therefore, the use of MRP with anatomical partial volume correction is of interest for dynamic PET studies.

A Computational Model Quantifies the Effect of Anatomical Variability on Velopharyngeal Function

ERIC Educational Resources Information Center

Inouye, Joshua M.; Perry, Jamie L.; Lin, Kant Y.; Blemker, Silvia S.

2015-01-01

Purpose: This study predicted the effects of velopharyngeal (VP) anatomical parameters on VP function to provide a greater understanding of speech mechanics and aid in the treatment of speech disorders. Method: We created a computational model of the VP mechanism using dimensions obtained from magnetic resonance imaging measurements of 10 healthy…

The effect of peer assisted learning (PAL) on anatomic competencies of prospective student’s biology teachers

NASA Astrophysics Data System (ADS)

Diana, S.

2018-05-01

Research about the effect of Peer Assisted Learning (PAL) strategy on Plant Anatomy Course, which aims to improve anatomic competencies of prospective student’s biology teacher, has been done. This study used a quasi-experimental pre-test post-test control group design. The draft includes a group of students who were given a pre-test which is then followed by observing the PAL treatment process and post-test. The other students group (control) was given the pre-test and post-test only. The PAL program began with a discussion between the lecturer and the tutor about the pretest results and then discussion between the tutors and their tutees in the class about the responses items. After that, all students were assigned to answer a set of response items, and then did the posttest. The results showed that the PAL strategy can increase student’s anatomic literacy significantly and can increase student’s anatomic lab skills no significantly. Thus the PAL strategy implementation has a potential to improve student’s anatomic competencies. The generally students weaknesses were they lack practice in interpreting of research results in the graphs form and rarely shared about anatomic lab skills. All students respond positively to the PAL strategy.

Gallbladder Duplication: Evaluation, Treatment, and Classification

DTIC Science & Technology

2010-02-01

2009; revised 16 December 2009; accepted 16 December 2009h o th 0 d Key words: Duplicate gallbladder; Hepatobiliary embryology ; Multiple gallbladders...anatomic variations [5]. These three types vary depending upon the embryologic development and occur in the same manner as duplicated gallbladders. Given... embryology and adds a third group that occurs when there is a combination of types 1 and 2 anatomy. The triple combined group occurs from a split in

Analysis of the arterial anatomical variations of thyroid gland: anatomic guide for surgical neck dissection.

PubMed

Ray, B; Pugazhandhi, B; D'Souza, A S; Saran, S; Fasil, M; Srinivasa, R S

2012-01-01

Aim of this study was to establish preliminary data on the variations of arterial supply of thyroid gland in Karnataka population. The anterior triangles in the neck of formalin fixed cadavers were dissected. The length, branching pattern, number and length of branches of superior thyroid artery (STA) were noted. We measured the length of inferior thyroid artery (ITA) from its point of emergence from thyrocervical trunk (TCT) to lower pole of thyroid gland. The length of the external carotid artery (ECA), TCT from the point of its emergence to the point of its branching was noted. We noted the number of branches from ITA and TCT. Presence of any additional artery supplying the thyroid gland was searched for. Difference in the length of STA and ITA between the two sexes and sides were noted. Statistical analysis was done by Student's t-test. In our study the maximum length of STA was 5.34cm and that of ITA was 5.07cm and there were no statistically significant side-to-side differences in level of bifurcation. Observations of the present study on the course and branching pattern of arteries around thyroid gland will help in easier approach during thyroid surgeries and interventional techniques (Tab. 1, Fig. 3, Ref. 38).

Variation in the Level of Grain Defect Light Flecks and Spots on Cattle Hides

PubMed Central

Nafstad, O; Grønstøl, H

2001-01-01

The occurrence of hide damage light flecks and spots was determined on tanned hides from 28 herds during a period of 8 to 12 months. Light flecks and spots are described as small areas of grain loss up to 3 mm in diameter that are seen on dyed crust cattle leather. Damage was found on 75.8% of all hides. The neck and shoulders were the anatomical region with the highest prevalence of damage. Sixty-eight per cent of all hides had light flecks and spots in this region. The forelimbs and dewlap were the anatomical region with the second highest occurrence with a prevalence of 39.1%. This distribution corresponded to the known distribution of lice in cattle. No significant differences were observed in age, sex, prevalence of lice in the herd assessed in March or infestations with different lice species. The frequency of light flecks and spots varied significantly during the year. The frequency was highest in the late winter and early spring, decreased significantly during the summer and was lowest in the autumn. This variation supported the importance of lice in the development of light flecks and spots and suggested a relatively long healing period for the damages induced by lice. PMID:11455905

Subprimal purchasing and merchandising decisions for pork: relationship to retail yield and fabrication time.

PubMed

Lorenzen, C L; Griffin, D B; Dockerty, T R; Walter, J P; Johnson, H K; Savell, J W

1996-01-01

Boxed pork was obtained to represent four different purchase specifications (different anatomical separation locations and[or] external fat trim levels) common in the pork industry to conduct a study of retail yields and labor requirements. Bone-in loins (n = 180), boneless loins (n = 94), and Boston butts (n = 148) were assigned randomly to fabrication styles within subprimals. When comparing cutting styles within subprimals, it was evident that cutting style affected percentage of retail yield and cutting time. When more bone-in cuts were prepared from bone-in loin subprimals, retail yields ranged from 92.80 +/- .61 to 95.28 +/- .45%, and processing times ranged from 222.57 +/- 10.13 to 318.99 +/- 7.85 s, from the four suppliers. When more boneless cuts were prepared from bone-in loin subprimals, retail yields ranged from 71.12 +/- 1.10 to 77.92 +/- .77% and processing times ranged from 453.49 +/- 8.95 to 631.09 +/- 15.04 s from the different loins. Comparing boneless to bone-in cuts from bone-in loins resulted in lower yields and required greater processing times. Significant variations in yields and times were found within cutting styles. These differences seemed to have been the result of variation in supplier fat trim level and anatomical separation (primarily scribe length).

Clinical significance of circumportal pancreas, a rare congenital anomaly, in pancreatectomy.

PubMed

Ohtsuka, Takao; Mori, Yasuhisa; Ishigami, Kousei; Fujimoto, Takaaki; Miyasaka, Yoshihiro; Nakata, Kohei; Ohuchida, Kenoki; Nagai, Eishi; Oda, Yoshinao; Shimizu, Shuji; Nakamura, Masafumi

2017-08-01

Circumportal pancreas is a rare congenital pancreatic anomaly. The aim of this study was to clarify the clinical characteristics of patients with circumportal pancreases undergoing pancreatectomy. The medical records of 508 patients who underwent pancreatectomy were retrospectively reviewed. The prevalence of circumportal pancreas and related anatomical variations were assessed. Surgical procedures and postoperative outcomes were compared in patients with and without circumportal pancreas. Circumportal pancreas was observed in 9 of the 508 patients (1.7%). In all nine patients, the portal vein was completely encircled by the pancreatic parenchyma above the level of the splenoportal junction, and the main pancreatic duct ran dorsal to the portal vein. The rate of variant hepatic artery did not differ significantly in patients with and without circumportal pancreas. Pancreatic fistula developed more frequently in patients with than without circumportal pancreas (44% vs. 14%, p = 0.03), but other clinical parameters did not differ significantly in these two groups. Despite being rare, circumportal pancreas may increase the risk of postoperative pancreatic fistula in patients undergoing pancreatectomy. However, a prospective, large-cohort study is necessary to determine the real incidence of relevant anatomical variations and the definitive clinical significance of this rare anomaly. Copyright © 2016 Elsevier Inc. All rights reserved.

Stereoscopic vascular models of the head and neck: A computed tomography angiography visualization.

PubMed

Cui, Dongmei; Lynch, James C; Smith, Andrew D; Wilson, Timothy D; Lehman, Michael N

2016-01-01

Computer-assisted 3D models are used in some medical and allied health science schools; however, they are often limited to online use and 2D flat screen-based imaging. Few schools take advantage of 3D stereoscopic learning tools in anatomy education and clinically relevant anatomical variations when teaching anatomy. A new approach to teaching anatomy includes use of computed tomography angiography (CTA) images of the head and neck to create clinically relevant 3D stereoscopic virtual models. These high resolution images of the arteries can be used in unique and innovative ways to create 3D virtual models of the vasculature as a tool for teaching anatomy. Blood vessel 3D models are presented stereoscopically in a virtual reality environment, can be rotated 360° in all axes, and magnified according to need. In addition, flexible views of internal structures are possible. Images are displayed in a stereoscopic mode, and students view images in a small theater-like classroom while wearing polarized 3D glasses. Reconstructed 3D models enable students to visualize vascular structures with clinically relevant anatomical variations in the head and neck and appreciate spatial relationships among the blood vessels, the skull and the skin. © 2015 American Association of Anatomists.

Quantum squeezed state analysis of spontaneous ultra weak light photon emission of practitioners of meditation and control subjects.

PubMed

Van Wijk, Eduard P A; Van Wijk, Roeland; Bajpai, Rajendra P

2008-05-01

Research on human ultra-weak photon emission (UPE) has suggested a typical human emission anatomic percentage distribution pattern. It was demonstrated that emission intensities are lower in long-term practitioners of meditation as compared to control subjects. The percent contribution of emission from different anatomic locations was not significantly different for meditation practitioners and control subjects. Recently, a procedure was developed to analyze the fluctuations in the signals by measuring probabilities of detecting different numbers of photons in a bin and correct these for background noise. The procedure was tested utilizing the signal from three different body locations of a single subject, demonstrating that probabilities have non-classical features and are well described by the signal in a coherent state from the three body sites. The values indicate that the quantum state of photon emitted by the subject could be a coherent state in the subject being investigated. The objective in the present study was to systematically quantify, in subjects with long-term meditation experience and subjects without this experience, the photon count distribution of 12 different locations. Data show a variation in quantum state parameters within each individual subject as well as variation in quantum state parameters between the groups.

NOTE: Development and preliminary evaluation of a prototype audiovisual biofeedback device incorporating a patient-specific guiding waveform

NASA Astrophysics Data System (ADS)

Venkat, Raghu B.; Sawant, Amit; Suh, Yelin; George, Rohini; Keall, Paul J.

2008-06-01

The aim of this research was to investigate the effectiveness of a novel audio-visual biofeedback respiratory training tool to reduce respiratory irregularity. The audiovisual biofeedback system acquires sample respiratory waveforms of a particular patient and computes a patient-specific waveform to guide the patient's subsequent breathing. Two visual feedback models with different displays and cognitive loads were investigated: a bar model and a wave model. The audio instructions were ascending/descending musical tones played at inhale and exhale respectively to assist in maintaining the breathing period. Free-breathing, bar model and wave model training was performed on ten volunteers for 5 min for three repeat sessions. A total of 90 respiratory waveforms were acquired. It was found that the bar model was superior to free breathing with overall rms displacement variations of 0.10 and 0.16 cm, respectively, and rms period variations of 0.77 and 0.33 s, respectively. The wave model was superior to the bar model and free breathing for all volunteers, with an overall rms displacement of 0.08 cm and rms periods of 0.2 s. The reduction in the displacement and period variations for the bar model compared with free breathing was statistically significant (p = 0.005 and 0.002, respectively); the wave model was significantly better than the bar model (p = 0.006 and 0.005, respectively). Audiovisual biofeedback with a patient-specific guiding waveform significantly reduces variations in breathing. The wave model approach reduces cycle-to-cycle variations in displacement by greater than 50% and variations in period by over 70% compared with free breathing. The planned application of this device is anatomic and functional imaging procedures and radiation therapy delivery.

A new method to predict anatomical outcome after idiopathic macular hole surgery.

PubMed

Liu, Peipei; Sun, Yaoyao; Dong, Chongya; Song, Dan; Jiang, Yanrong; Liang, Jianhong; Yin, Hong; Li, Xiaoxin; Zhao, Mingwei

2016-04-01

To investigate whether a new macular hole closure index (MHCI) could predict anatomic outcome of macular hole surgery. A vitrectomy with internal limiting membrane peeling, air-fluid exchange, and gas tamponade were performed on all patients. The postoperative anatomic status of the macular hole was defined by spectral-domain OCT. MHCI was calculated as (M+N)/BASE based on the preoperative OCT status. M and N were the curve lengths of the detached photoreceptor arms, and BASE was the length of the retinal pigment epithelial layer (RPE layer) detaching from the photoreceptors. Postoperative anatomical outcomes were divided into three grades: A (bridge-like closure), B (good closure), and C (poor closure or no closure). Correlation analysis was performed between anatomical outcomes and MHCI. Receiver operating characteristic (ROC) curves were derived for MHCI, indicating good model discrimination. ROC curves were also assessed by the area under the curve, and cut-offs were calculated. Other predictive parameters reported previously, which included the MH minimum, the MH height, the macular hole index (MHI), the diameter hole index (DHI), and the tractional hole index (THI) had been compared as well. MHCI correlated significantly with postoperative anatomical outcomes (r = 0.543, p = 0.000), but other predictive parameters did not. The areas under the curves indicated that MHCI could be used as an effective predictor of anatomical outcome. Cut-off values of 0.7 and 1.0 were obtained for MHCI from ROC curve analysis. MHCI demonstrated a better predictive effect than other parameters, both in the correlation analysis and ROC analysis. MHCI could be an easily measured and accurate predictive index for postoperative anatomical outcomes.

Mental rotation and the human body: Children's inflexible use of embodiment mirrors that of adults.

PubMed

Krüger, Markus; Ebersbach, Mirjam

2017-12-25

Adults' mental rotation performance with body-like stimuli is enhanced if these stimuli are anatomically compatible with a human body, but decreased by anatomically incompatible stimuli. In this study, we investigated these effects for kindergartners and first-graders: When asked to mentally rotate cube configurations attached with human body parts in an anatomically compatible way, allowing for the projection of a human body, children performed better than with pure cube combinations. By contrast, when body parts were attached in an anatomically incompatible way, disallowing the projection of a human body, children performed worse than with pure combinations. This experiment is of specific interest against the background of two different theoretical approaches concerning imagery and the motor system in development: One approach assumes an increasing integration of motor processes and imagery over time that enables older children and adults to requisition motor resources for imagery processes, while the other postulates that imagery stems from early sensorimotor processes in the first place, and is disentangled from it over time. The finding that children of the two age groups tested show exactly the same effects as adults when mentally rotating anatomically compatible and incompatible stimuli is interpreted in favour of the latter approach. Statement of contribution What is already known on this subject? In mental rotation, adults perform better when rotating anatomically possible stimuli as compared to rotating standard cube combinations. Performance is worse when rotating anatomically impossible stimuli. What does this study add? The present study shows that children's mental transformations mirror those of adults in these respects. In case of the anatomically impossible stimuli, this highlights an inflexible use of embodiment in both age groups. This is in line with the Piagetian assumption of imagery being based on sensorimotor processes. © 2017 The British Psychological Society.

Variations of the origin of collateral branches emerging from the posterior aspect of the brachial plexus

PubMed Central

2007-01-01

Background The frequency of variation found in the arrangement and distribution of the branches in the brachial plexus, make this anatomical region extremely complicated. The medical concerns involved with these variations include anesthetic blocks, surgical approaches, interpreting tumor or traumatic nervous compressions having unexplained clinical symptoms (sensory loss, pain, wakefulness and paresis), and the possibility of these structures becoming compromised. The clinical importance of these variations is discussed in the light of their differential origins. Methods The anatomy of brachial plexus structures from 46 male and 11 female cadaverous specimens were studied. The 40–80 year-old specimens were obtained from the Universidad Industrial de Santander's Medical Faculty's Anatomy Department (dissection laboratory). Parametric measures were used for calculating results. Results Almost half (47.1%) of the evaluated plexuses had collateral variations. Subscapular nerves were the most varied structure, including the presence of a novel accessory nerve. Long thoracic nerve variations were present, as were the absence of C5 or C7 involvement, and late C7 union with C5–C6. Conclusion Further studies are needed to confirm the existence of these variations in a larger sample of cadaver specimens. PMID:17587464

Anatomical Variability of the Posterior Communicating Artery.

PubMed

Gunnal, Sandhya Arvind; Farooqui, Mujibuddin S; Wabale, Rajendra N

2018-01-01

Although posterior communicating artery (PCoA) is a smaller branch of the internal carotid artery, it gives the main contribution in the formation of circle of Willis (CW) by communicating with the internal carotid arterial system and the vertebro-basilar arterial system. The size of PCoA varies frequently. The present work aims to study the PCoA regarding its morphology, morphometry, and symmetry. This study was conducted on 170 human cadaveric brains. Brains were dissected carefully and delicately to expose all components of CW, especially PCoA. Morphological variations of PCoA were noted along with its morphometry and symmetry. Morphological variations of PCoA were aplasia (3.52%), hypoplasia (25.29%), fenestration (0.58%), and persistent fetal pattern (16.47%). In the present study, we found the five different types of terminations of PCoA. Type I termination was the most common type, seen in 92.94% of cases, Type II termination was seen in 1.17%, Type III and Type IV terminations both were seen in 0.58%, and Type V was seen in 1.17%. The mean length of PCoA was 15.9 mm and 15.3 mm on the right and left sides, respectively. The mean diameter of PCoA was 2.1 mm and 1.9 mm on the right and left sides, respectively. Symmetry of PCoA was seen in 65.29% and asymmetric PCoA was seen in 34.70% of cases. The present study provides the complete description of PCoA regarding its morphology, symmetry, and morphometry. Awareness of these anatomical variations is important in neurovascular procedures.

Anatomical variations in the origins of the celiac axis and the superior mesenteric artery: MDCT angiographic findings and their probable embryological mechanisms.

PubMed

Wang, Yi; Cheng, Cheng; Wang, Lu; Li, Ran; Chen, Jin-hua; Gong, Shui-gen

2014-08-01

To identify the spectrum and prevalence of anatomical variations in the origin of the celiac axis (CA), the superior mesenteric artery (SMA) and their major branches by using multidetector computed tomographic (MDCT) angiography. A retrospective evaluation was carried out on 1,500 abdominal MDCT angiography images. The aortic origins of the CA, the SMA and their major branch patterns were investigated. Normal aortic origins of CA and SMA were noted in 1,347 (89.8%) patients. Seven types of CA and SMA origin variants were identified in 153 (10.2%) patients. The three most common variations were hepatomesenteric trunk (67 patients, 4.47%), celiomesenteric trunk (CMT) (51 patients, 3.4%) and splenomesenteric trunk (18 patients, 1.2%). An evaluation of CMT was classified as long (34 patients, 66.7%) or short (17 patients, 33.3%) subtypes, compared with the length of the common trunk. Further CMT classification was based on the origin of the left gastric artery: subtype I, 26 patients (53.1%); subtype II, 5 patients (10.2%); subtype III, 15 patients (30.6%); subtype IV, 3 patients (6.1%). Dislocation interruption, incomplete interruption and persistence of the longitudinal anastomosis could be the embryological mechanisms of the variant origins of the CA, the SMA and their major branches. • Aortic origins of CA, SMA and their major branches were investigated. • Celiomesenteric trunk includes several different subtypes and configurations. • Probable embryological mechanisms of origin variants in these observed arteries were discussed. • Origin variants in these observed arteries have wide-ranging health implications.

Anatomic variations of the renal vessels pertinent to transperitoneal vascular control in the management of trauma.

PubMed

Kaneko, Naoyuki; Kobayashi, Yasushi; Okada, Yoshiaki

2008-05-01

Operative exposure and control of the renal vessels through a transabdominal retroperitoneal (TARP) approach has been advocated for emergency management of renal trauma. The pertinent anatomic variations of the renal vasculature have not been well described. In 190 cadavers, the renal vessels were examined. The first 20 cadavers were examined via TARP approach, and 170 cadavers were investigated after evisceration. The findings were interpreted as they might relate to the TARP approach to the renal pedicle. The renal artery (RA) originated dorsally or inferiorly to the left renal vein (RV) in 70% of the cadavers on each side. Additional RAs emerging below the inferior mesenteric artery were present in 2.4% of cadavers on the right side and 1.8% on the left. Approach to the inferior vena cava (IVC) adequate for the management of trauma through the TARP approach was impossible, although it has been recommended in some research. The clinically significant incidence of variations was as follows: 47% multiple RAs, 13% multiple RVs, and 50% of at least 1 RA that coursed superior to the right RV on the right margin of the IVC. Knowledge of the varied anatomy of the renal vessels facilitates a safe approach to the kidneys in trauma management. The varied and unpredictable anatomy of the renal vasculature requires prompt change when the TARP approach fails to provide access to the vessels. In such cases, the colon should be mobilized promptly. On the right side of the IVC, the vessels are located so as to require clamping together almost always.

Torcular Herophili classification and evaluation of dural venous sinus variations using digital subtraction angiography and magnetic resonance venographies.

PubMed

Gökçe, Erkan; Pınarbaşılı, Tansu; Acu, Berat; Fırat, M Murat; Erkorkmaz, Ünal

2014-08-01

The configurations of cerebral veins and dural venous sinuses differ not only between individuals, but also between the two brain hemispheres of an individual, making the anatomical classification of the cerebral veins difficult. We evaluated the superior dural venous sinuses and classified their types and variations using magnetic resonance venography (MRV) and digital substraction angiography (DSA). A total of 394 patients were studied retrospectively. Superior dural venous sinuses were evaluated and the confluence of the sinuses was classified on 2-dimensional time-of-flight MRV, contrast-enhanced 3-dimensional spoiled gradient recalled echo magnetic resonance imaging, and/or cerebral DSA. Confluens sinuum was divided into three types: true confluence, partial confluence, and non-confluence. Of the three types, partial confluence (type II) was most frequently seen. Co-dominance of the transverse sinuses was most frequently observed. An occipital sinus was observed in 15 % of the patients. There were statistically significant differences between the left transverse sinus agenesis and the presence of the occipital sinus (p < 0.001), between the co-presence of the partial confluence type torcular and the occipital sinus (p = 0.040), and between the co-presence of the fenestrated straight sinus and the occipital sinus (p = 0.010). Although anatomical variations of dural venous sinuses are seen frequently, classification of venous sinuses helps surgeons in preoperative evaluation and management, and prevention of possible complications. In this study, we think that a comprehensive evaluation and classification of dural venous sinuses is a significant contribution to the literature.

An application of principal component analysis to the clavicle and clavicle fixation devices.

PubMed

Daruwalla, Zubin J; Courtis, Patrick; Fitzpatrick, Clare; Fitzpatrick, David; Mullett, Hannan

2010-03-26

Principal component analysis (PCA) enables the building of statistical shape models of bones and joints. This has been used in conjunction with computer assisted surgery in the past. However, PCA of the clavicle has not been performed. Using PCA, we present a novel method that examines the major modes of size and three-dimensional shape variation in male and female clavicles and suggests a method of grouping the clavicle into size and shape categories. Twenty-one high-resolution computerized tomography scans of the clavicle were reconstructed and analyzed using a specifically developed statistical software package. After performing statistical shape analysis, PCA was applied to study the factors that account for anatomical variation. The first principal component representing size accounted for 70.5 percent of anatomical variation. The addition of a further three principal components accounted for almost 87 percent. Using statistical shape analysis, clavicles in males have a greater lateral depth and are longer, wider and thicker than in females. However, the sternal angle in females is larger than in males. PCA confirmed these differences between genders but also noted that men exhibit greater variance and classified clavicles into five morphological groups. This unique approach is the first that standardizes a clavicular orientation. It provides information that is useful to both, the biomedical engineer and clinician. Other applications include implant design with regard to modifying current or designing future clavicle fixation devices. Our findings support the need for further development of clavicle fixation devices and the questioning of whether gender-specific devices are necessary.

Probabilistic Tractography Recovers a Rostrocaudal Trajectory of Connectivity Variability in the Human Insular Cortex

PubMed Central

Cerliani, Leonardo; Thomas, Rajat M; Jbabdi, Saad; Siero, Jeroen CW; Nanetti, Luca; Crippa, Alessandro; Gazzola, Valeria; D'Arceuil, Helen; Keysers, Christian

2012-01-01

The insular cortex of macaques has a wide spectrum of anatomical connections whose distribution is related to its heterogeneous cytoarchitecture. Although there is evidence of a similar cytoarchitectural arrangement in humans, the anatomical connectivity of the insula in the human brain has not yet been investigated in vivo. In the present work, we used in vivo probabilistic white-matter tractography and Laplacian eigenmaps (LE) to study the variation of connectivity patterns across insular territories in humans. In each subject and hemisphere, we recovered a rostrocaudal trajectory of connectivity variation ranging from the anterior dorsal and ventral insula to the dorsal caudal part of the long insular gyri. LE suggested that regional transitions among tractography patterns in the insula occur more gradually than in other brain regions. In particular, the change in tractography patterns was more gradual in the insula than in the medial premotor region, where a sharp transition between different tractography patterns was found. The recovered trajectory of connectivity variation in the insula suggests a relation between connectivity and cytoarchitecture in humans resembling that previously found in macaques: tractography seeds from the anterior insula were mainly found in limbic and paralimbic regions and in anterior parts of the inferior frontal gyrus, while seeds from caudal insular territories mostly reached parietal and posterior temporal cortices. Regions in the putative dysgranular insula displayed more heterogeneous connectivity patterns, with regional differences related to the proximity with either putative granular or agranular regions. Hum Brain Mapp 33:2005–2034, 2012. © 2011 Wiley Periodicals, Inc. PMID:21761507

Effect of Anatomically Realistic Full-Head Model on Activation of Cortical Neurons in Subdural Cortical Stimulation—A Computational Study

NASA Astrophysics Data System (ADS)

Seo, Hyeon; Kim, Donghyeon; Jun, Sung Chan

2016-06-01

Electrical brain stimulation (EBS) is an emerging therapy for the treatment of neurological disorders, and computational modeling studies of EBS have been used to determine the optimal parameters for highly cost-effective electrotherapy. Recent notable growth in computing capability has enabled researchers to consider an anatomically realistic head model that represents the full head and complex geometry of the brain rather than the previous simplified partial head model (extruded slab) that represents only the precentral gyrus. In this work, subdural cortical stimulation (SuCS) was found to offer a better understanding of the differential activation of cortical neurons in the anatomically realistic full-head model than in the simplified partial-head models. We observed that layer 3 pyramidal neurons had comparable stimulation thresholds in both head models, while layer 5 pyramidal neurons showed a notable discrepancy between the models; in particular, layer 5 pyramidal neurons demonstrated asymmetry in the thresholds and action potential initiation sites in the anatomically realistic full-head model. Overall, the anatomically realistic full-head model may offer a better understanding of layer 5 pyramidal neuronal responses. Accordingly, the effects of using the realistic full-head model in SuCS are compelling in computational modeling studies, even though this modeling requires substantially more effort.

A Model of Regularization Parameter Determination in Low-Dose X-Ray CT Reconstruction Based on Dictionary Learning.

PubMed

Zhang, Cheng; Zhang, Tao; Zheng, Jian; Li, Ming; Lu, Yanfei; You, Jiali; Guan, Yihui

2015-01-01

In recent years, X-ray computed tomography (CT) is becoming widely used to reveal patient's anatomical information. However, the side effect of radiation, relating to genetic or cancerous diseases, has caused great public concern. The problem is how to minimize radiation dose significantly while maintaining image quality. As a practical application of compressed sensing theory, one category of methods takes total variation (TV) minimization as the sparse constraint, which makes it possible and effective to get a reconstruction image of high quality in the undersampling situation. On the other hand, a preliminary attempt of low-dose CT reconstruction based on dictionary learning seems to be another effective choice. But some critical parameters, such as the regularization parameter, cannot be determined by detecting datasets. In this paper, we propose a reweighted objective function that contributes to a numerical calculation model of the regularization parameter. A number of experiments demonstrate that this strategy performs well with better reconstruction images and saving of a large amount of time.

ConfidenHT™ System for Diagnostic Mapping of Renal Nerves.

PubMed

Tsioufis, Costas; Dimitriadis, Kyriakos; Tsioufis, Panagiotis; Patras, Rafael; Papadoliopoulou, Maria; Petropoulou, Zoi; Konstantinidis, Dimitris; Tousoulis, Dimitrios

2018-05-19

To summarize the evidence regarding the distribution of renal nerves and their patterns of anatomic variations in animal and human settings. Moreover, the methodology and results of studies regarding renal nerve stimulation (RNS) in both preclinical and clinical models are presented. There are differences regarding the number and the size of renal fibers, as well as their distance from the lumen in the diverse parts of the main renal arteries and the branches. In both animals and humans, RNS is safe and results in an increase of blood pressure (BP) while the effect on heart rate varies. In this context, the ConfidenHT™ system constitutes an integrated solution for effective RNS in humans. Due to the diversity of renal nerve anatomy in humans, arterial areas for more effective renal denervation cannot be homogenously defined. The concept of mapping of renal nerves can improve completeness of renal denervation therapies by means of integrated RNS solutions such as the ConfidenHT™ system.

Effectiveness of Plastinated Anatomical Specimens Depicting Common Sports Injuries to Enhance Musculoskeletal Injury Evaluation Education

ERIC Educational Resources Information Center

Tamura, Kaori; Stickley, Christopher D.; Labrash, Steven J.; Lozanoff, Scott

2014-01-01

Context: Plastination techniques have emerged as effective methods for preserving human tissue and enabling human specimens to be utilized in a fashion similar to anatomical models with much greater accuracy. Opportunities to observe and experience human specimens in classroom settings should be beneficial to undergraduate and graduate students in…

Anatomic changes due to interspecific grafting in cassava (Manihot esculenta).

PubMed

Bomfim, N; Ribeiro, D G; Nassar, N M A

2011-05-31

Cassava rootstocks of varieties UnB 201 and UnB 122 grafted with scions of Manihot fortalezensis were prepared for anatomic study. The roots were cut, stained with safranin and alcian blue, and examined microscopically, comparing them with sections taken from ungrafted roots. There was a significant decrease in number of pericyclic fibers, vascular vessels and tyloses in rootstocks. They exhibited significant larger vessels. These changes in anatomic structure are a consequence of genetic effects caused by transference of genetic material from scion to rootstock. The same ungrafted species was compared. This is the first report on anatomic changes due to grafting in cassava.

The enigma of effective path length for (18) O enrichment in leaf water of conifers.

PubMed

Roden, John; Kahmen, Ansgar; Buchmann, Nina; Siegwolf, Rolf

2015-12-01

The Péclet correction is often used to predict leaf evaporative enrichment and requires an estimate of effective path length (L). Studies to estimate L in conifer needles have produced unexpected patterns based on Péclet theory and leaf anatomy. We exposed seedlings of six conifer species to different vapour pressure deficits (VPD) in controlled climate chambers to produce steady-state leaf water enrichment (in (18) O). We measured leaf gas exchange, stable oxygen isotopic composition (δ(18) O) of input and plant waters as well as leaf anatomical characteristics. Variation in bulk needle water δ(18) O was strongly related to VPD. Conifer needles had large amounts of water within the vascular strand that was potentially unenriched (up to 40%). Both standard Craig-Gordon and Péclet models failed to accurately predict conifer leaf water δ(18) O without taking into consideration the unenriched water in the vascular strand and variable L. Although L was linearly related to mesophyll thickness, large within-species variation prevented the development of generalizations that could allow a broader use of the Péclet effect in predictive models. Our results point to the importance of within needle water pools and isolating mechanisms that need further investigation in order to integrate Péclet corrections with 'two compartment' leaf water concepts. © 2015 John Wiley & Sons Ltd.

Pencil Beam Scanning Proton Therapy for Rhabdomyosarcoma of the Biliary Tract.

PubMed

Pater, Luke; Turpin, Brian; Mascia, Anthony

2017-10-05

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood with 250-350 cases diagnosed annually in the United States. Biliary tract rhabdomyosarcoma is rare, representing <1% of the RMS cases. Due to its location, resection is clinically challenging, and functional complications exist and persist from biliary obstruction. The anatomical location of this tumor presents both opportunities and challenges for pencil beam scanning proton therapy. Proton therapy offers a dosimetric and clinical advantage by sparing the healthy liver, stomach, contra-lateral kidney and bowel. Motion management and anatomical variations, such as intestinal filling or weight loss, requiring routine dosimetric evaluation and possible adaptive treatment planning, present challenges for the use of proton therapy. By taking advantage of the superior dose distribution of proton radiation, assessing the impact of tumor and anatomy motion, and performing regular dose evaluations, biliary tract RMS is an ideal diagnosis for pencil beam scanning proton therapy.

Role of targeted magnetic resonance imaging sequences in the surgical management of anterior skull base pathology.

PubMed

Chawla, S; Bowman, J; Gandhi, M; Panizza, B

2017-01-01

The skull base is a highly complex anatomical region that provides passage for important nerves and vessels as they course into and out of the cranial cavity. Key to the management of pathology in this region is a thorough understanding of the anatomy, with its variations, and the relationship of various neurovascular structures to the pathology in question. Targeted high-resolution magnetic resonance imaging on high field strength magnets can enable the skull base surgeon to understand this intricate relationship and deal with the pathology from a position of relative advantage. With the help of case studies, this paper illustrates the application of specialised magnetic resonance techniques to study pathology of the orbital apex in particular. The fine anatomical detail provided gives surgeons the ability to design an endonasal endoscopic procedure appropriate to the anatomy of the pathology.

Current surgical strategies for total arthroplasty in valgus knee

PubMed Central

Nikolopoulos, Dimitrios; Michos, Ioannis; Safos, George; Safos, Petros

2015-01-01

The majority of orthopaedic surgeons even currently agree that primary total arthroplasty in valgus knees with a deformity of more than ten degrees may prove challenging. The unique sets of bone and soft tissue abnormalities that must be addressed at the time of the operation make accurate axis restoration, component orientation and joint stability attainment a difficult task. Understanding the specific pathologic anatomic changes associated with the valgus knee is a prerequisite so as to select the proper surgical method, to optimize component position and restore soft-tissue balance. The purpose of this article is to review the valgus knee anatomical variations, to assess the best pre-operative planning and to evaluate how to choose the grade of constraint of the implant. It will also be underlying the up-to-date main approaches and surgical techniques be proposed in the English literature both for bone cuts and soft tissue management of valgus knees. PMID:26191494

Low-Dimensional Statistics of Anatomical Variability via Compact Representation of Image Deformations.

PubMed

Zhang, Miaomiao; Wells, William M; Golland, Polina

2016-10-01

Using image-based descriptors to investigate clinical hypotheses and therapeutic implications is challenging due to the notorious "curse of dimensionality" coupled with a small sample size. In this paper, we present a low-dimensional analysis of anatomical shape variability in the space of diffeomorphisms and demonstrate its benefits for clinical studies. To combat the high dimensionality of the deformation descriptors, we develop a probabilistic model of principal geodesic analysis in a bandlimited low-dimensional space that still captures the underlying variability of image data. We demonstrate the performance of our model on a set of 3D brain MRI scans from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Our model yields a more compact representation of group variation at substantially lower computational cost than models based on the high-dimensional state-of-the-art approaches such as tangent space PCA (TPCA) and probabilistic principal geodesic analysis (PPGA).

The influence of anatomical and physiological parameters on the interference voltage at the input of unipolar cardiac pacemakers in low frequency electric fields.

PubMed

Joosten, S; Pammler, K; Silny, J

2009-02-07

The problem of electromagnetic interference of electronic implants such as cardiac pacemakers has been well known for many years. An increasing number of field sources in everyday life and occupational environment leads unavoidably to an increased risk for patients with electronic implants. However, no obligatory national or international safety regulations exist for the protection of this patient group. The aim of this study is to find out the anatomical and physiological worst-case conditions for patients with an implanted pacemaker adjusted to unipolar sensing in external time-varying electric fields. The results of this study with 15 volunteers show that, in electric fields, variation of the interference voltage at the input of a cardiac pacemaker adds up to 200% only because of individual factors. These factors should be considered in human studies and in the setting of safety regulations.

How to quantify conduits in wood?

PubMed

Scholz, Alexander; Klepsch, Matthias; Karimi, Zohreh; Jansen, Steven

2013-01-01

Vessels and tracheids represent the most important xylem cells with respect to long distance water transport in plants. Wood anatomical studies frequently provide several quantitative details of these cells, such as vessel diameter, vessel density, vessel element length, and tracheid length, while important information on the three dimensional structure of the hydraulic network is not considered. This paper aims to provide an overview of various techniques, although there is no standard protocol to quantify conduits due to high anatomical variation and a wide range of techniques available. Despite recent progress in image analysis programs and automated methods for measuring cell dimensions, density, and spatial distribution, various characters remain time-consuming and tedious. Quantification of vessels and tracheids is not only important to better understand functional adaptations of tracheary elements to environment parameters, but will also be essential for linking wood anatomy with other fields such as wood development, xylem physiology, palaeobotany, and dendrochronology.

The Total Artificial Heart in End-Stage Congenital Heart Disease.

PubMed

Villa, Chet R; Morales, David L S

2017-01-01

The development of durable ventricular assist devices (VADs) has improved mortality rates and quality of life in patients with end stage heart failure. While the use of VADs has increased dramatically in recent years, there is limited experience with VAD implantation in patients with complex congenital heart disease (CHD), despite the fact that the number of patients with end stage CHD has grown due to improvements in surgical and medical care. VAD use has been limited in patients with CHD and end stage heart failure due to anatomic (systemic right ventricle, single ventricle, surgically altered anatomy, valve dysfunction, etc.) and physiologic constraints (diastolic dysfunction). The total artificial heart (TAH), which has right and left sided pumps that can be arranged in a variety of orientations, can accommodate the anatomic variation present in CHD patients. This review provides an overview of the potential use of the TAH in patients with CHD.

The Total Artificial Heart in End-Stage Congenital Heart Disease

PubMed Central

Villa, Chet R.; Morales, David L. S.

2017-01-01

The development of durable ventricular assist devices (VADs) has improved mortality rates and quality of life in patients with end stage heart failure. While the use of VADs has increased dramatically in recent years, there is limited experience with VAD implantation in patients with complex congenital heart disease (CHD), despite the fact that the number of patients with end stage CHD has grown due to improvements in surgical and medical care. VAD use has been limited in patients with CHD and end stage heart failure due to anatomic (systemic right ventricle, single ventricle, surgically altered anatomy, valve dysfunction, etc.) and physiologic constraints (diastolic dysfunction). The total artificial heart (TAH), which has right and left sided pumps that can be arranged in a variety of orientations, can accommodate the anatomic variation present in CHD patients. This review provides an overview of the potential use of the TAH in patients with CHD. PMID:28536530

A rare variant of internal anatomy of a third mandibular molar: a case report.

PubMed

Nimigean, V; Nimigean, Vanda Roxana; Sălăvăstru, D I

2011-01-01

The several anatomical variations existing in the root canal system may contribute to failure of the root canal therapy. Knowledge of the internal dental morphology is a complex and extremely important point for planning and performing endodontic therapy. This paper reports the case of a left mandibular third molar that presented only one dental conical root and only one aberrant radicular canal with an initial annular portion situated in the coronar third of the root and a linear portion at the level of the other two thirds of the dental root, which opened through an apical foramen. Root canal therapy and case management are described. Features like wide crown access, adequate illumination and use of exploring files where important for successful completion of the endodontic treatment. The treatment was performed through conventional methods. This clinical case constitutes a rare anatomical variant of internal radicular morphology.

Endodontic management of middle mesial canal of the mandibular molar

PubMed Central

Sundaresh, K J; Srinivasan, Raghu; Mallikarjuna, Rachappa; Rajalbandi, Sandeep

2013-01-01

Thorough knowledge of root canal morphology and unusual anatomy of the tooth is critical for successful endodontic treatment. Although the most common configuration is two roots and three root canals, mandibular molars might have many different combinations. In the literature, it is less described about three mesial canals and two distal canals in mandibular second molars, indicating a rare anatomical configuration. A case of unusual root canal morphology is presented to demonstrate anatomical variations in mandibular molars. Endodontic therapy was performed in a mandibular second molar with five separate canals, three mesial and two distal. This report points out the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise might have ended in failure. In conclusion, every attempt should be made to find and treat all root canals of a tooth. PMID:23349182

Standardizing the intrinsic brain: Towards robust measurement of inter-individual variation in 1000 functional connectomes

PubMed Central

Yan, Chao-Gan; Craddock, R. Cameron; Zuo, Xi-Nian; Zang, Yu-Feng; Milham, Michael P.

2014-01-01

As researchers increase their efforts to characterize variations in the functional connectome across studies and individuals, concerns about the many sources of nuisance variation present and their impact on resting state fMRI (R-fMRI) measures continue to grow. Although substantial within-site variation can exist, efforts to aggregate data across multiple sites such as the 1000 Functional Connectomes Project (FCP) and International Neuroimaging Data-sharing Initiative (INDI) datasets amplify these concerns. The present work draws upon standardization approaches commonly used in the microarray gene expression literature, and to a lesser extent recent imaging studies, and compares them with respect to their impact on relationships between common R-fMRI measures and nuisance variables (e.g., imaging site, motion), as well as phenotypic variables of interest (age, sex). Standardization approaches differed with regard to whether they were applied post-hoc vs. during pre-processing, and at the individual vs. group level; additionally they varied in whether they addressed additive effects vs. additive + multiplicative effects, and were parametric vs. non-parametric. While all standardization approaches were effective at reducing undesirable relationships with nuisance variables, post-hoc approaches were generally more effective than global signal regression (GSR). Across approaches, correction for additive effects (global mean) appeared to be more important than for multiplicative effects (global SD) for all R-fMRI measures, with the exception of amplitude of low frequency fluctuations (ALFF). Group-level post-hoc standardizations for mean-centering and variance-standardization were found to be advantageous in their ability to avoid the introduction of artifactual relationships with standardization parameters; though results between individual and group-level post-hoc approaches were highly similar overall. While post-hoc standardization procedures drastically increased test–retest (TRT) reliability for ALFF, modest reductions were observed for other measures after post-hoc standardizations—a phenomena likely attributable to the separation of voxel-wise from global differences among subjects (global mean and SD demonstrated moderate TRT reliability for these measures). Finally, the present work calls into question previous observations of increased anatomical specificity for GSR over mean centering, and draws attention to the near equivalence of global and gray matter signal regression. PMID:23631983

Ion-mediated enhancement of xylem hydraulic conductivity in four Acer species: relationships with ecological and anatomical features.

PubMed

Nardini, Andrea; Dimasi, Federica; Klepsch, Matthias; Jansen, Steven

2012-12-01

The 'ionic effect', i.e., changes in xylem hydraulic conductivity (k(xyl)) due to variation of the ionic sap composition in vessels, was studied in four Acer species growing in contrasting environments differing in water availability. Hydraulic measurements of the ionic effect were performed together with measurements on the sap electrical conductivity, leaf water potential and vessel anatomy. The low ionic effect recorded in Acer pseudoplatanus L. and Acer campestre L. (15.8 and 14.7%, respectively), which represented two species from shady and humid habitats, was associated with a low vessel grouping index, high sap electrical conductivity and least negative leaf water potential. Opposite traits were found for Acer monspessulanum L. and Acer platanoides L., which showed an ionic effect of 23.6 and 23.1%, respectively, and represent species adapted to higher irradiance and/or lower water availability. These findings from closely related species provide additional support that the ionic effect could function as a compensation mechanism for embolism-induced loss of k(xyl), either as a result of high evaporative demand or increased risk of hydraulic failure.

Cone beam computed tomography evaluation and endodontic management of permanent mandibular second molar with four roots: A rare case report and literature review

PubMed Central

Rajasekhara, Subhashini; Sharath Chandra, SM; Parthasarathy, Late Bharath

2014-01-01

The morphological variation in the number of roots and root canals, especially in multi-rooted teeth is a constant challenge for diagnosis and successful endodontic therapy. Knowledge of the most common anatomic characteristics and their possible variations is fundamental. Although, endodontic management of four-rooted mandibular first molars have been observed on a few occasions in the literature, to the best of our knowledge four-rooted mandibular second molars having two mesial and two distal roots have not been reported. This paper highlights endodontic management of mandibular second molar with four roots (two mesial and two distal) with one canal in each root and its cone beam computed tomography (CBCT) evaluation which was primarily done for post treatment assessment for diagnosing post-endodontic complications, at the same time confirmed our radiographic diagnosis of this variation. This also helped us portraying the anatomy of this rare variation. PMID:25125856

Evaluation of scattered light distributions of cw-transillumination for functional diagnostic of rheumatic disorders in interphalangeal joints

NASA Astrophysics Data System (ADS)

Prapavat, Viravuth; Schuetz, Rijk; Runge, Wolfram; Beuthan, Juergen; Mueller, Gerhard J.

1995-12-01

This paper presents in-vitro-studies using the scattered intensity distribution obtained by cw- transillumination to examine the condition of rheumatic disorders of interphalangeal joints. Inflammation of joints, due to rheumatic diseases, leads to changes in the synovial membrane, synovia composition and content, and anatomic geometrical variations. Measurements have shown that these rheumatic induced inflammation processes result in a variation in optical properties of joint systems. With a scanning system the interphalangeal joint is transilluminated with diode lasers (670 nm, 905 nm) perpendicular to the joint cavity. The detection of the entire distribution of the transmitted radiation intensity was performed with a CCD camera. As a function of the structure and optical properties of the transilluminated volume we achieved distributions of scattered radiation which show characteristic variations in intensity and shape. Using signal and image processing procedures we evaluated the measured scattered distributions regarding their information weight, shape and scale features. Mathematical methods were used to find classification criteria to determine variations of the joint condition.

Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy

PubMed Central

Diogo, Rui; Esteve-Altava, Borja; Smith, Christopher; Boughner, Julia C.; Rasskin-Gutman, Diego

2015-01-01

How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual’s survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts—their topological patterns relative to each other—using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures. PMID:26452269

Patient specific anatomy: the new area of anatomy based on computer science illustrated on liver.

PubMed

Soler, Luc; Mutter, Didier; Pessaux, Patrick; Marescaux, Jacques

2015-01-01

Over the past century, medical imaging has brought a new revolution: internal anatomy of a patient could be seen without any invasive technique. This revolution has highlighted the two main limits of current anatomy: the anatomical description is physician dependent, and the average anatomy is more and more frequently insufficient to describe anatomical variations. These drawbacks can sometimes be so important that they create mistakes but they can be overcome through the use of 3D patient-specific surgical anatomy. In this article, we propose to illustrate such improvement of standard anatomy on liver. We first propose a general scheme allowing to easily compare the four main liver anatomical descriptions by Takasaki, Goldsmith and Woodburne, Bismuth and Couinaud. From this general scheme we propose four rules to apply in order to correct these initial anatomical definitions. Application of these rules allows to correct usual vascular topological mistakes of standard anatomy. We finally validate such correction on a database of 20 clinical cases compared to the 111 clinical cases of a Couinaud article. Out of the 20 images of the database, we note a revealing difference in 14 cases (70%) on at least one important branch of the portal network. Only six cases (30%) do not present a revealing difference between both labellings. We also show that the right portal fissure location on our 20 cases defined between segment V and VI of our anatomical definition is well correlated with the real position described by Couinaud on 111 cases, knowing that the theoretical position was only found in 46 cases out of 111, i.e., 41.44% of cases with the non-corrected Couinaud definition. We have proposed a new anatomical segmentation of the liver based on four main rules to apply in order to correct topological errors of the four main standard segmentations. Our validation clearly illustrates that this new definition corrects the large amount of mistakes created by the current standard definitions, increased by physician interpretation that can vary from one case to another.

Anatomical Network Comparison of Human Upper and Lower, Newborn and Adult, and Normal and Abnormal Limbs, with Notes on Development, Pathology and Limb Serial Homology vs. Homoplasy.

PubMed

Diogo, Rui; Esteve-Altava, Borja; Smith, Christopher; Boughner, Julia C; Rasskin-Gutman, Diego

2015-01-01

How do the various anatomical parts (modules) of the animal body evolve into very different integrated forms (integration) yet still function properly without decreasing the individual's survival? This long-standing question remains unanswered for multiple reasons, including lack of consensus about conceptual definitions and approaches, as well as a reasonable bias toward the study of hard tissues over soft tissues. A major difficulty concerns the non-trivial technical hurdles of addressing this problem, specifically the lack of quantitative tools to quantify and compare variation across multiple disparate anatomical parts and tissue types. In this paper we apply for the first time a powerful new quantitative tool, Anatomical Network Analysis (AnNA), to examine and compare in detail the musculoskeletal modularity and integration of normal and abnormal human upper and lower limbs. In contrast to other morphological methods, the strength of AnNA is that it allows efficient and direct empirical comparisons among body parts with even vastly different architectures (e.g. upper and lower limbs) and diverse or complex tissue composition (e.g. bones, cartilages and muscles), by quantifying the spatial organization of these parts-their topological patterns relative to each other-using tools borrowed from network theory. Our results reveal similarities between the skeletal networks of the normal newborn/adult upper limb vs. lower limb, with exception to the shoulder vs. pelvis. However, when muscles are included, the overall musculoskeletal network organization of the upper limb is strikingly different from that of the lower limb, particularly that of the more proximal structures of each limb. Importantly, the obtained data provide further evidence to be added to the vast amount of paleontological, gross anatomical, developmental, molecular and embryological data recently obtained that contradicts the long-standing dogma that the upper and lower limbs are serial homologues. In addition, the AnNA of the limbs of a trisomy 18 human fetus strongly supports Pere Alberch's ill-named "logic of monsters" hypothesis, and contradicts the commonly accepted idea that birth defects often lead to lower integration (i.e. more parcellation) of anatomical structures.

Patient specific anatomy: the new area of anatomy based on computer science illustrated on liver

PubMed Central

Mutter, Didier; Pessaux, Patrick; Marescaux, Jacques

2015-01-01

Background Over the past century, medical imaging has brought a new revolution: internal anatomy of a patient could be seen without any invasive technique. This revolution has highlighted the two main limits of current anatomy: the anatomical description is physician dependent, and the average anatomy is more and more frequently insufficient to describe anatomical variations. These drawbacks can sometimes be so important that they create mistakes but they can be overcome through the use of 3D patient-specific surgical anatomy. Methods In this article, we propose to illustrate such improvement of standard anatomy on liver. We first propose a general scheme allowing to easily compare the four main liver anatomical descriptions by Takasaki, Goldsmith and Woodburne, Bismuth and Couinaud. From this general scheme we propose four rules to apply in order to correct these initial anatomical definitions. Application of these rules allows to correct usual vascular topological mistakes of standard anatomy. We finally validate such correction on a database of 20 clinical cases compared to the 111 clinical cases of a Couinaud article. Results Out of the 20 images of the database, we note a revealing difference in 14 cases (70%) on at least one important branch of the portal network. Only six cases (30%) do not present a revealing difference between both labellings. We also show that the right portal fissure location on our 20 cases defined between segment V and VI of our anatomical definition is well correlated with the real position described by Couinaud on 111 cases, knowing that the theoretical position was only found in 46 cases out of 111, i.e., 41.44% of cases with the non-corrected Couinaud definition. Conclusions We have proposed a new anatomical segmentation of the liver based on four main rules to apply in order to correct topological errors of the four main standard segmentations. Our validation clearly illustrates that this new definition corrects the large amount of mistakes created by the current standard definitions, increased by physician interpretation that can vary from one case to another. PMID:29075611

Neuronal metabolomics by ion mobility mass spectrometry: cocaine effects on glucose and selected biogenic amine metabolites in the frontal cortex, striatum, and thalamus of the rat.

PubMed

Kaplan, Kimberly A; Chiu, Veronica M; Lukus, Peter A; Zhang, Xing; Siems, William F; Schenk, James O; Hill, Herbert H

2013-02-01

We report results of studies of global and targeted neuronal metabolomes by ambient pressure ion mobility mass spectrometry. The rat frontal cortex, striatum, and thalamus were sampled from control nontreated rats and those treated with acute cocaine or pargyline. Quantitative evaluations were made by standard additions or isotopic dilution. The mass detection limit was ~100 pmol varying with the analyte. Targeted metabolites of dopamine, serotonin, and glucose followed the rank order of distribution expected between the anatomical areas. Data was evaluated by principal component analysis on 764 common metabolites (identified by m/z and reduced mobility). Differences between anatomical areas and treatment groups were observed for 53 % of these metabolites using principal component analysis. Global and targeted metabolic differences were observed between the three anatomical areas with contralateral differences between some areas. Following drug treatments, global and targeted metabolomes were found to shift relative to controls and still maintained anatomical differences. Pargyline reduced 3,4-dihydroxyphenylacetic acid below detection limits, and 5-HIAA varied between anatomical regions. Notable findings were: (1) global metabolomes were different between anatomical areas and were altered by acute cocaine providing a broad but targeted window of discovery for metabolic changes produced by drugs of abuse; (2) quantitative analysis was demonstrated using isotope dilution and standard addition; (3) cocaine changed glucose and biogenic amine metabolism in the anatomical areas tested; and (4) the largest effect of cocaine was on the glycolysis metabolome in the thalamus confirming inferences from previous positron emission tomography studies using 2-deoxyglucose.

Anatomic variations found on dissection of depressor septi nasi muscles in cadavers.

PubMed

Ebrahimi, Ali; Nejadsarvari, Nasrin; Motamedi, Mohammad Hosein Kalantar; Rezaee, Maryam; Koushki, Ehsan Shams

2012-01-01

To define variations of the depressor septi muscle in Iranians; to provide guidance for modification of this muscle during rhinoplasty in patients with an active muscle and short upper lip; and to correlate our findings with our clinical experience to develop the applied algorithms. This study was conducted by dissecting 82 depressor septi nasi muscles in 41 Iranian cadavers. Origin and insertion points of each muscle were studied. Three variations were found in muscle insertion points: periosteal, orbicularis oris, and floating. Forty-four percent of the muscles were inserted into the periosteum of the maxilla (n = 36); 39% of muscles were inserted into the orbicularis oris muscle (n = 32); and 17% were diminutive or floating (n = 14). Periosteal insertion was thicker and stronger than the other variations. In all cadavers, the origin of the muscle was medial crus of alar cartilage and caudal of the nasal septum. This cadaveric dissection showed that the percentage of depressor septi muscle insertions is not similar to that found in other surveys. In this study, periosteal insertion of the depressor septi muscle was the most common variation.

Temporary Blindness after Inferior Alveolar Nerve Block.

PubMed

Barodiya, Animesh; Thukral, Rishi; Agrawal, Shaila Mahendra; Rai, Anshul; Singh, Siddharth

2017-03-01

Inferior Alveolar Nerve Block (IANB) anaesthesia is one of the common procedures in dental clinic. This procedure is safe, but complications may still occur. Ocular complications such as diplopia, loss of vision, or ophthalmoplegia are extremely rare. This case report explains an event where due to individual anatomic variation of the sympathetic vasoconstrictor nerve and maxillary and middle meningeal arteries, intravascular administration of anaesthetic agent caused unusual ocular signs and symptoms such as temporary blindness.

Proton therapy versus intensity modulated x-ray therapy in the treatment of prostate cancer: Estimating secondary cancer risks

NASA Astrophysics Data System (ADS)

Fontenot, Jonas David

External beam radiation therapy is used to treat nearly half of the more than 200,000 new cases of prostate cancer diagnosed in the United States each year. During a radiation therapy treatment, healthy tissues in the path of the therapeutic beam are exposed to high doses. In addition, the whole body is exposed to a low-dose bath of unwanted scatter radiation from the pelvis and leakage radiation from the treatment unit. As a result, survivors of radiation therapy for prostate cancer face an elevated risk of developing a radiogenic second cancer. Recently, proton therapy has been shown to reduce the dose delivered by the therapeutic beam to normal tissues during treatment compared to intensity modulated x-ray therapy (IMXT, the current standard of care). However, the magnitude of stray radiation doses from proton therapy, and their impact on this incidence of radiogenic second cancers, was not known. The risk of a radiogenic second cancer following proton therapy for prostate cancer relative to IMXT was determined for 3 patients of large, median, and small anatomical stature. Doses delivered to healthy tissues from the therapeutic beam were obtained from treatment planning system calculations. Stray doses from IMXT were taken from the literature, while stray doses from proton therapy were simulated using a Monte Carlo model of a passive scattering treatment unit and an anthropomorphic phantom. Baseline risk models were taken from the Biological Effects of Ionizing Radiation VII report. A sensitivity analysis was conducted to characterize the uncertainty of risk calculations to uncertainties in the risk model, the relative biological effectiveness (RBE) of neutrons for carcinogenesis, and inter-patient anatomical variations. The risk projections revealed that proton therapy carries a lower risk for radiogenic second cancer incidence following prostate irradiation compared to IMXT. The sensitivity analysis revealed that the results of the risk analysis depended only weakly on uncertainties in the risk model and inter-patient variations. Second cancer risks were sensitive to changes in the RBE of neutrons. However, the findings of the study were qualitatively consistent for all patient sizes and risk models considered, and for all neutron RBE values less than 100.

Anatomical, biochemical, and photosynthetic responses to recent allopolyploidy in Glycine dolichocarpa (Fabaceae).

PubMed

Coate, Jeremy E; Luciano, Amelia K; Seralathan, Vasu; Minchew, Kevin J; Owens, Tom G; Doyle, Jeff J

2012-01-01

Previous studies have shown that polyploidy has pronounced effects on photosynthesis. Most of these studies have focused on synthetic or recently formed autopolyploids, and comparatively little is known about the integrated effects of natural allopolyploidy, which involves hybridity and genome doubling and often incorporates multiple genotypes through recurrent origins and lineage recombination. Glycine dolichocarpa (designated T2) is a natural allotetraploid with multiple origins. We quantified 21 anatomical, biochemical, and physiological phenotypes relating to photosynthesis in T2 and its diploid progenitors, G. tomentella (D3) and G. syndetika (D4). To assess how direction of cross affects these phenotypes, we included three T2 accessions having D3-like plastids (T2(D3)) and two accessions having D4-like plastids (T2(D4)). T2 accessions were transgressive (more extreme than any diploid accession) for 17 of 21 phenotypes, and species means differed significantly in T2 vs. both progenitors for four of 21 phenotypes (higher for guard cell length, electron transport capacity [J(max)] per palisade cell, and J(max) per mesophyll cell; lower for palisade cells per unit leaf area). Within T2, four of 21 parameters differed significantly between T2(D3) and T2(D4) (palisade cell volume; chloroplast number and volume per unit leaf area; and J(max) per unit leaf area). T2 is characterized by transgressive photosynthesis-related phenotypes (including an ca. 2-fold increase in J(max) per cell), as well as by significant intraspecies variation correlating with plastid type. These data indicate prominent roles for both nucleotypic effects and cytoplasmic factors in photosynthetic responses to allopolyploidy.

Bayesian reconstruction and use of anatomical a priori information for emission tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bowsher, J.E.; Johnson, V.E.; Turkington, T.G.

1996-10-01

A Bayesian method is presented for simultaneously segmenting and reconstructing emission computed tomography (ECT) images and for incorporating high-resolution, anatomical information into those reconstructions. The anatomical information is often available from other imaging modalities such as computed tomography (CT) or magnetic resonance imaging (MRI). The Bayesian procedure models the ECT radiopharmaceutical distribution as consisting of regions, such that radiopharmaceutical activity is similar throughout each region. It estimates the number of regions, the mean activity of each region, and the region classification and mean activity of each voxel. Anatomical information is incorporated by assigning higher prior probabilities to ECT segmentations inmore » which each ECT region stays within a single anatomical region. This approach is effective because anatomical tissue type often strongly influences radiopharmaceutical uptake. The Bayesian procedure is evaluated using physically acquired single-photon emission computed tomography (SPECT) projection data and MRI for the three-dimensional (3-D) Hoffman brain phantom. A clinically realistic count level is used. A cold lesion within the brain phantom is created during the SPECT scan but not during the MRI to demonstrate that the estimation procedure can detect ECT structure that is not present anatomically.« less

Novel analysis of 4DCT imaging quantifies progressive increases in anatomic dead space during mechanical ventilation in mice.

PubMed

Kim, Elizabeth H; Preissner, Melissa; Carnibella, Richard P; Samarage, Chaminda R; Bennett, Ellen; Diniz, Marcio A; Fouras, Andreas; Zosky, Graeme R; Jones, Heather D

2017-09-01

Increased dead space is an important prognostic marker in early acute respiratory distress syndrome (ARDS) that correlates with mortality. The cause of increased dead space in ARDS has largely been attributed to increased alveolar dead space due to ventilation/perfusion mismatching and shunt. We sought to determine whether anatomic dead space also increases in response to mechanical ventilation. Mice received intratracheal lipopolysaccharide (LPS) or saline and mechanical ventilation (MV). Four-dimensional computed tomography (4DCT) scans were performed at onset of MV and after 5 h of MV. Detailed measurements of airway volumes and lung tidal volumes were performed using image analysis software. The forced oscillation technique was used to obtain measures of airway resistance, tissue damping, and tissue elastance. The ratio of airway volumes to total tidal volume increased significantly in response to 5 h of mechanical ventilation, regardless of LPS exposure, and airways demonstrated significant variation in volumes over the respiratory cycle. These findings were associated with an increase in tissue elastance (decreased lung compliance) but without changes in tidal volumes. Airway volumes increased over time with exposure to mechanical ventilation without a concomitant increase in tidal volumes. These findings suggest that anatomic dead space fraction increases progressively with exposure to positive pressure ventilation and may represent a pathological process. NEW & NOTEWORTHY We demonstrate that anatomic dead space ventilation increases significantly over time in mice in response to mechanical ventilation. The novel functional lung-imaging techniques applied here yield sensitive measures of airway volumes that may have wide applications. Copyright © 2017 the American Physiological Society.

Effects of anatomical position on esophageal transit time: A biomagnetic diagnostic technique

PubMed Central

Cordova-Fraga, Teodoro; Sosa, Modesto; Wiechers, Carlos; la Roca-Chiapas, Jose Maria De; Moreles, Alejandro Maldonado; Bernal-Alvarado, Jesus; Huerta-Franco, Raquel

2008-01-01

AIM: To study the esophageal transit time (ETT) and compare its mean value among three anatomical inclinations of the body; and to analyze the correlation of ETT to body mass index (BMI). METHODS: A biomagnetic technique was implemented to perform this study: (1) The transit time of a magnetic marker (MM) through the esophagus was measured using two fluxgate sensors placed over the chest of 14 healthy subjects; (2) the ETT was assessed in three anatomical positions (at upright, fowler, and supine positions; 90º, 45º and 0º, respectively). RESULTS: ANOVA and Tuckey post-hoc tests demonstrated significant differences between ETT mean of the different positions. The ETT means were 5.2 ± 1.1 s, 6.1 ± 1.5 s, and 23.6 ± 9.2 s for 90º, 45º and 0º, respectively. Pearson correlation results were r = -0.716 and P < 0.001 by subjects’ anatomical position, and r = -0.024 and P > 0.05 according the subject’s BMI. CONCLUSION: We demonstrated that using this biomagnetic technique, it is possible to measure the ETT and the effects of the anatomical position on the ETT. PMID:18837088

Intervisceral artery origins in patients with abdominal aortic aneurysmal disease; evidence for systemic vascular remodelling.

PubMed

Bailey, Damian M; Evans, Tom G; Thomas, Kate Gower; White, Richard D; Twine, Chistopher P; Lewis, Michael H; Williams, Ian M

2016-08-01

What is the central question of this study? To what extent focal abdominal aortic aneurysmal (AAA) disease is associated with systemic remodelling of the vascular tree remains unknown. The present study examined whether anatomical differences exist between distances of the intervisceral artery origins and AAA location/size in patients with disease compared with healthy patients. What is the main finding and its importance? Intervisceral artery distances were shown to be consistently greater in AAA patients, highlighting the systemic nature of AAA disease that extends proximally to the abdominal aorta and its branches. The anatomical description of the natural variation in visceral artery origins has implications for the design of stent grafts and planning complex open aortic surgery. The initial histopathology of abdominal aortic aneurysmal (AAA) disease is atherosclerotic, later diverting towards a distinctive dilating rather than occlusive aortic phenotype. To what extent focal AAA disease is associated with systemic remodelling of the vascular tree remains unknown. The present study examined whether anatomical differences exist between the intervisceral artery origins and AAA location/size in patients with AAA disease (AAA+) relative to those without (AAA-). Preoperative contrast-enhanced computerized tomograms were reviewed in 90 consecutive AAA+ patients scheduled for open repair who underwent an infrarenal (n = 45), suprarenal (n = 26) or supracoeliac clamp (n = 19). These were compared with 39 age-matched AAA- control patients. Craniocaudal measurements were recorded from the distal origin of the coeliac artery to the superior mesenteric artery and from the origin of the superior mesenteric artery to both renal artery origins. Serial blood samples were obtained for estimation of the glomerular filtration rate before and after surgery. Intervisceral artery origins were shown to be consistently greater in AAA+ patients (P < 0.05 versus AAA-), although unrelated to AAA diameter (P > 0.05). Postoperative renal function became progressively more impaired the more proximal the clamp placement (estimated glomerular filtration rate for supracoeliac < suprarenal < infrarenal clamps, P < 0.05). These findings highlight the systemic nature of AAA disease that extends proximally to the abdominal aorta and its branches. The anatomical description of the natural variation in visceral artery origins has implications for the design of stent grafts and planning complex open aortic surgery. © 2016 The Authors. Experimental Physiology © 2016 The Physiological Society.

The surgical vascular anatomy of the minimally invasive lateral lumbar interbody approach: a cadaveric and radiographic analysis.

PubMed

Alkadhim, Mustafa; Zoccali, Carmine; Abbasifard, Salman; Avila, Mauricio J; Patel, Apar S; Sattarov, Kamran; Walter, Christina M; Baaj, Ali A

2015-11-01

The minimally invasive (MI) lateral lumbar interbody fusion (LLIF) approach has become increasingly popular for the treatment of degenerative lumbar spine disease. The neural anatomy of the lumbar plexus has been studied; however, the pertinent surgical vascular anatomy has not been examined in detail. The goal of this study is to examine the vascular structures that are relevant in relation to the MI-LLIF approach. Anatomic dissection of the lumbar spines and associated vasculature was performed in three embalmed, adult cadavers. Right and left surgeon perspective views during LLIF were for a total of six approaches. During the dissection, all vascular elements were noted and photographed, and anatomical relationships to the vertebral bodies and disc spaces were analyzed. In addition, several axial and sagittal MRI images of the lumbar spine were analyzed to complement the cadaveric analysis. The aorta descends along the left anterior aspect of lumbar vertebra with an average distance of 2.1 cm (range 1.9-2.3 cm) to the center of each intervertebral disc. The vena cava descends along the right anterior aspect of lumbar vertebrates with average distance of 1.4 cm (range 1.3-1.6 cm) to the center of the intervertebral disc. Each vertebral body has two lumbar arteries (direct branches from the aorta); one exits to the left and one to the right side of the vertebral body. The lumbar arteries pass underneath the sympathetic trunk, run in the superior margin of the vertebral body and extend all the way across it, with average length of 3.8 cm (range 2.5-5 cm). The mean distance between the arteries and the inferior plate of the superior disc space is 4.2 mm (range 2-5 mm) and mean distance of 3.1 cm (range 2.8-3.8 cm) between two arteries in adjacent vertebrae. One of the cadavers had an expected normal anatomical variation where the left arteries at L3-L4 anastomosed dorsally of the vertebral bodies at the middle of the intervertebral disc. Understanding the vascular anatomy of the lateral and anterior lumbar spine is paramount for successfully and safely executing the LLIF procedure. It is imperative to identify anatomical variations in lumbar arteries and veins with careful assessment of the preoperative imaging.

Refinement of Molecular Diagnostic Protocol of Auditory Neuropathy Spectrum Disorder

PubMed Central

Chang, Mun Young; Kim, Ah Reum; Kim, Nayoung K.D.; Lee, Chung; Park, Woong-Yang; Choi, Byung Yoon

2015-01-01

Abstract Auditory neuropathy spectrum disorder (ANSD) is a sensorineural hearing disorder caused by dysfunction of auditory neural conduction. ANSD has a heterogeneous etiology, including genetic factors; the response to cochlear implantation significantly varies depending on the etiology. The results of timely cochlear implantation for OTOF-related ANSD (DFNB9) have been reported to be good. Therefore, identifying the causative gene of ANSD, especially OTOF, is an important issue to rehabilitate these patients. Six sporadic ANSD subjects without anatomical abnormality of the cochlear nerve, including the 4 subjects that were previously reported to be without detectable OTOF mutation, were included. We performed targeted resequencing (TRS) of known deafness genes and multiphasic bioinformatics analyses of the data that ensured detection of capture failure and structural variations. Exclusion of SNP was also double checked. The TRS data previously obtained from 2 subjects were reanalyzed. Through this study, we detected 2 mutant alleles of OTOF from 5 (83.3%) of 6 ANSD subjects. All of the 5 subjects carried at least 1 mutant allele carrying p.R1939Q. This variant was categorized as a simple SNP (rs201326023) in the database and it resided in the exon with frequent capture failures, which previously led to exclusion of this variant from eligible candidacy mistakenly. In addition, we detected a structural variation within OTOF from a previously undiagnosed ANSD subject, which was the second structural variation reported in DFNB9 subjects to date. We identify a strong etiologic homogeneity of prelingual ANSD in case of the anatomically normal cochlear nerve in Koreans and now report DFNB9 as the single overwhelming cause. Multiphasic analysis of TRS data ensuring detection of capture failure and structural variations would be expected to reveal DFNB9 from a substantial portion of previously undiagnosed ANSD subjects in Koreans. Based on our results, we propose a novel strategy that incorporates imaging studies, prevalent mutation screening and multiphasic analysis of TRS data in a stepwise manner to correctly detect DFNB9 in Koreans. PMID:26632695

Glenoid version and size: does gender, ethnicity, or body size play a role?

PubMed

Piponov, Hristo Ivanov; Savin, David; Shah, Neal; Esposito, Domenic; Schwartz, Brian; Moretti, Vincent; Goldberg, Benjamin

2016-11-01

Variations in glenoid morphology among patients of different gender, body habitus, and ethnicity have been of interest for surgeons. Understanding these anatomical variations is a critical step in restoring normal glenohumeral structure during shoulder reconstruction surgery. Retrospective review of 108 patient shoulder CT scans was performed and glenoid version, AP diameter and height were measured. Statistical multiple regression models were used to investigate the ability of gender and ethnicity to predict glenoid AP diameter, height, and version independently of patient weight and height. The mean glenoid AP diameter was 24.7 ± 3.5, the mean glenoid height was 31.7 ± 3.7, and the mean glenoid version was 0.05 ± 9.05. According to our regression models, males would be expected to exhibit 8.4° more glenoid retroversion than females (p = 0.003) and have 2.9 mm larger glenoid height compared to females (p = 0.002). The predicted male glenoid AP diameter was 3.4 mm higher than that in females (p < 0.001). Hispanics demonstrated 6.4° more glenoid anteversion compared to African-Americans (p = 0.04). Asians exhibited 4.1 mm smaller glenoid AP diameters than African-Americans (p = 0.002). An increase of 25 kg in patient weight resulted in 1 mm increase in AP diameter (p = 0.01). Gender is the strongest independent predictor of glenoid size and version. Males exhibited a larger size and more retroverted glenoid. Patient height was found to be predictive of glenoid size only in patients of the same gender. Although variations in glenoid size and version are observed among ethnicities, larger sample size ethnic groups will be necessary to explore the precise relations. Surgeons should consider gender and ethnic variations in the pre-operative planning and surgical restoration of the native glenohumeral relationship. Anatomic Study.

Spread of activation and deactivation in the brain: does age matter?

PubMed Central

Gordon, Brian A.; Tse, Chun-Yu; Gratton, Gabriele; Fabiani, Monica

2014-01-01

Cross-sectional aging functional MRI results are sometimes difficult to interpret, as standard measures of activation and deactivation may confound variations in signal amplitude and spread, which however, may be differentially affected by age-related changes in various anatomical and physiological factors. To disentangle these two types of measures, here we propose a novel method to obtain independent estimates of the peak amplitude and spread of the BOLD signal in areas activated (task-positive) and deactivated (task-negative) by a Sternberg task, in 14 younger and 28 older adults. The peak measures indicated that, compared to younger adults, older adults had increased activation of the task-positive network, but similar levels of deactivation in the task-negative network. Measures of signal spread revealed that older adults had an increased spread of activation in task-positive areas, but a starkly reduced spread of deactivation in task-negative areas. These effects were consistent across regions within each network. Further, there was greater variability in the anatomical localization of peak points in older adults, leading to reduced cross-subject overlap. These results reveal factors that may confound the interpretation of studies of aging. Additionally, spread measures may be linked to local connectivity phenomena and could be particularly useful to analyze age-related deactivation patterns, complementing the results obtained with standard peak and region of interest analyses. PMID:25360115

Are there age induced morphologic variations of the superior glenoid labrum? About 100 shoulder arthroscopies.

PubMed

Clavert, Philippe; Kempf, Jean-François; Wolfram-Gabel, Renée; Kahn, Jean-Luc

2005-12-01

Different anterosuperior aspects of the glenoid labrum have already been described and are thought to be normal anatomical variations. The goals of this study were first to characterize these anterosuperior labral morphologies and then to analyze their variations in function of the patients' age. One hundred shoulder arthroscopies were recorded to study the macroscopic characteristics of the anterosuperior labrum of the glenohumeral joint and its relationships with the proximal insertion of the tendon of the long head of the biceps. Then, patients were divided into two groups in function of their age (below and over 30 years old). Morphological modifications of the labrum were found in function of the age of the patient with an increase of the nonpathologic "mobile labrum" type after 30 years (P=0.0423). Therefore a mobile and loosely attached superior labrum should not always be considered as abnormal, especially in case of patient older than 30 years.

Numeric and symbolic knowledge representation of cerebral cortex anatomy: methods and preliminary results.

PubMed

Dameron, O; Gibaud, B; Morandi, X

2004-06-01

The human cerebral cortex anatomy describes the brain organization at the scale of gyri and sulci. It is used as landmarks for neurosurgery as well as localization support for functional data analysis or inter-subject data comparison. Existing models of the cortex anatomy either rely on image labeling but fail to represent variability and structural properties or rely on a conceptual model but miss the inner 3D nature and relations of anatomical structures. This study was therefore conducted to propose a model of sulco-gyral anatomy for the healthy human brain. We hypothesized that both numeric knowledge (i.e., image-based) and symbolic knowledge (i.e., concept-based) have to be represented and coordinated. In addition, the representation of this knowledge should be application-independent in order to be usable in various contexts. Therefore, we devised a symbolic model describing specialization, composition and spatial organization of cortical anatomical structures. We also collected numeric knowledge such as 3D models of shape and shape variation about cortical anatomical structures. For each numeric piece of knowledge, a companion file describes the concept it refers to and the nature of the relationship. Demonstration software performs a mapping between the numeric and the symbolic aspects for browsing the knowledge base.

Chinook wind barosinusitis: an anatomic evaluation.

PubMed

Rudmik, Luke; Muzychuk, Adam; Oddone Paolucci, Elizabeth; Mechor, Brad

2009-01-01

Chinook, or föhn, is a weather phenomenon characterized by a rapid influx of warm, high-pressured winds into a specific location. Pressure changes associated with chinook winds induce facial pain similar to acute sinusitis. The purpose of this study was to determine the relationship between sinonasal anatomy and chinook headaches. Retrospective computed tomography (CT) sinonasal anatomy analysis of 38 patients with chinook headaches and 27 controls (no chinook headaches). The chinook headache status was blinded from the CT reviewer. Forty-one sinonasal anatomy variants, Lund-Mackay status, and sinus size (cm(3)) were recorded. There were three statistically significant sinonasal anatomy differences between patients with and without chinook headaches. The presence of a concha bullosa and sphenoethmoidal cell (Onodi cell) appeared to predispose to chinook headaches (p = 0.004). Chinook headache patients had larger maxillary sinus size (right, p = 0.015, and left, p = 0.002). The Lund-Mackay score was higher in the control patients (p = 0.003) indicating that chronic sinusitis does not play a role in chinook headaches. Chinook winds are a common source of facial pain and pressure. This is the first study to show that sinonasal anatomic variations may be a predisposing factor. Anatomic variants may induce facial pain by blocking the natural sinus ostia, thus preventing adequate pressure equilibrium.

Gene Expression Programs of Human Smooth Muscle Cells: Tissue-Specific Differentiation and Prognostic Significance in Breast Cancers

PubMed Central

Chi, Jen-Tsan; Rodriguez, Edwin H; Wang, Zhen; Nuyten, Dimitry S. A; Mukherjee, Sayan; van de Rijn, Matt; van de Vijver, Marc J.; Hastie, Trevor; Brown, Patrick O

2007-01-01

Smooth muscle is present in a wide variety of anatomical locations, such as blood vessels, various visceral organs, and hair follicles. Contraction of smooth muscle is central to functions as diverse as peristalsis, urination, respiration, and the maintenance of vascular tone. Despite the varied physiological roles of smooth muscle cells (SMCs), we possess only a limited knowledge of the heterogeneity underlying their functional and anatomic specializations. As a step toward understanding the intrinsic differences between SMCs from different anatomical locations, we used DNA microarrays to profile global gene expression patterns in 36 SMC samples from various tissues after propagation under defined conditions in cell culture. Significant variations were found between the cells isolated from blood vessels, bronchi, and visceral organs. Furthermore, pervasive differences were noted within the visceral organ subgroups that appear to reflect the distinct molecular pathways essential for organogenesis as well as those involved in organ-specific contractile and physiological properties. Finally, we sought to understand how this diversity may contribute to SMC-involving pathology. We found that a gene expression signature of the responses of vascular SMCs to serum exposure is associated with a significantly poorer prognosis in human cancers, potentially linking vascular injury response to tumor progression. PMID:17907811

Can we safely deform a plate to fit every bone? Population-based fit assessment and finite element deformation of a distal tibial plate.

PubMed

Harith, Hazreen; Schmutz, Beat; Malekani, Javad; Schuetz, Michael A; Yarlagadda, Prasad K

2016-03-01

Anatomically precontoured plates are commonly used to treat periarticular fractures. A well-fitting plate can be used as a tool for anatomical reduction of the fractured bone. Recent studies highlighted that some plates fit poorly for many patients due to considerable shape variations between bones of the same anatomical site. While it is impossible to design one shape that fits all, it is also burdensome for the manufacturers and hospitals to produce, store and manage multiple plate shapes without the certainty of utilization by a patient population. In this study, we investigated the number of shapes required for maximum fit within a given dataset, and if they could be obtained by manually deforming the original plate. A distal medial tibial plate was automatically positioned on 45 individual tibiae, and the optimal deformation was determined iteratively using finite element analysis simulation. Within the studied dataset, we found that: (i) 89% fit could be achieved with four shapes, (ii) 100% fit was impossible through mechanical deformation, and (iii) the deformations required to obtain the four plate shapes were safe for the stainless steel plate for further clinical use. The proposed framework is easily transferable to other orthopaedic plates. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Gene expression programs of human smooth muscle cells: tissue-specific differentiation and prognostic significance in breast cancers.

PubMed

Chi, Jen-Tsan; Rodriguez, Edwin H; Wang, Zhen; Nuyten, Dimitry S A; Mukherjee, Sayan; van de Rijn, Matt; van de Vijver, Marc J; Hastie, Trevor; Brown, Patrick O

2007-09-01

Smooth muscle is present in a wide variety of anatomical locations, such as blood vessels, various visceral organs, and hair follicles. Contraction of smooth muscle is central to functions as diverse as peristalsis, urination, respiration, and the maintenance of vascular tone. Despite the varied physiological roles of smooth muscle cells (SMCs), we possess only a limited knowledge of the heterogeneity underlying their functional and anatomic specializations. As a step toward understanding the intrinsic differences between SMCs from different anatomical locations, we used DNA microarrays to profile global gene expression patterns in 36 SMC samples from various tissues after propagation under defined conditions in cell culture. Significant variations were found between the cells isolated from blood vessels, bronchi, and visceral organs. Furthermore, pervasive differences were noted within the visceral organ subgroups that appear to reflect the distinct molecular pathways essential for organogenesis as well as those involved in organ-specific contractile and physiological properties. Finally, we sought to understand how this diversity may contribute to SMC-involving pathology. We found that a gene expression signature of the responses of vascular SMCs to serum exposure is associated with a significantly poorer prognosis in human cancers, potentially linking vascular injury response to tumor progression.

Cell size and wall dimensions drive distinct variability of earlywood and latewood density in Northern Hemisphere conifers.

PubMed

Björklund, Jesper; Seftigen, Kristina; Schweingruber, Fritz; Fonti, Patrick; von Arx, Georg; Bryukhanova, Marina V; Cuny, Henri E; Carrer, Marco; Castagneri, Daniele; Frank, David C

2017-11-01

Interannual variability of wood density - an important plant functional trait and environmental proxy - in conifers is poorly understood. We therefore explored the anatomical basis of density. We hypothesized that earlywood density is determined by tracheid size and latewood density by wall dimensions, reflecting their different functional tasks. To determine general patterns of variability, density parameters from 27 species and 349 sites across the Northern Hemisphere were correlated to tree-ring width parameters and local climate. We performed the same analyses with density and width derived from anatomical data comprising two species and eight sites. The contributions of tracheid size and wall dimensions to density were disentangled with sensitivity analyses. Notably, correlations between density and width shifted from negative to positive moving from earlywood to latewood. Temperature responses of density varied intraseasonally in strength and sign. The sensitivity analyses revealed tracheid size as the main determinant of earlywood density, while wall dimensions become more influential for latewood density. Our novel approach of integrating detailed anatomical data with large-scale tree-ring data allowed us to contribute to an improved understanding of interannual variations of conifer growth and to illustrate how conifers balance investments in the competing xylem functions of hydraulics and mechanical support. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

A need for logical and consistent anatomical nomenclature for cutaneous nerves of the limbs.

PubMed

Gest, Thomas R; Burkel, William E; Cortright, Gerald W

2009-01-01

The system of anatomical nomenclature needs to be logical and consistent. However, variations in translation to English of the Latin and Greek terminology used in Nomina Anatomica and Terminologia Anatomica have led to some inconsistency in the nomenclature of cutaneous nerves in the limbs. An historical review of cutaneous nerve nomenclature reveals that there are two general naming conventions: one primarily American and one primarily British. The American convention presents cutaneous nerves of the limbs in the format "medial brachial cutaneous nerve," while the British convention presents the same nerve as "medial cutaneous nerve of the arm," thereby translating "brachii" to "of the arm." If logically and consistently applied throughout the body, the British convention would rename the sural nerve to the "nerve of the calf," the brachial artery would become the "artery of the arm," the femoral nerve would be "nerve of the thigh," and femur would be "bone of the thigh" or "thigh bone." The British convention leads to many other nomenclatural inconsistencies, which would seem to make learning anatomy more difficult for the beginning student. In this era of contracting anatomy curricula, every effort should be made to keep anatomical nomenclature simple, logical, and consistent. Copyright 2009 American Association of Anatomists.

TU-AB-303-02: A Novel Surrogate to Identify Anatomical Changes During Radiotherapy of Head and Neck Cancer Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gros, S; Roeske, J; Surucu, M

Purpose: To develop a novel method to monitor external anatomical changes in head and neck cancer patients in order to help guide adaptive radiotherapy decisions. Methods: The method, developed in MATLAB, reveals internal anatomical changes based on variations observed in external anatomy. Weekly kV-CBCT scans from 11 Head and neck patients were retrospectively analyzed. The pre-processing step first corrects each CBCT for artifacts and removes pixels from the immobilization mask to produce an accurate external contour of the patient’s skin. After registering the CBCTs to the initial planning CT, the external contours from each CBCT (CBCTn) are transferred to themore » first week — reference — CBCT{sub 1}. Contour radii, defined as the distances between an external contour and the central pixel of each CBCT slice, are calculated for each scan at angular increments of 1 degree. The changes in external anatomy are then quantified by the difference in radial distance between the external contours of CBCT1 and CBCTn. The radial difference is finally displayed on a 2D intensity map (angle vs radial distance difference) in order to highlight regions of interests with significant changes. Results: The 2D radial difference maps provided qualitative and quantitative information, such as the location and the magnitude of external contour divergences and the rate at which these deviations occur. With this method, anatomical changes due to tumor volume shrinkage and patient weight loss were clearly identified and could be correlated with the under-dosage of targets or over-dosage of OARs. Conclusion: This novel method provides an efficient tool to visualize 3D external anatomical modification on a single 2D map. It quickly pinpoints the location of differences in anatomy during the course of radiotherapy, which can help determine if a treatment plan needs to be adapted.« less

A systematic review of animal predation creating pierced shells: implications for the archaeological record of the Old World

PubMed Central

Rosin, Zuzanna M.; Tryjanowski, Piotr

2017-01-01

Background The shells of molluscs survive well in many sedimentary contexts and yield information about the diet of prehistoric humans. They also yield evidence of symbolic behaviours through their use as beads for body adornments. Researchers often analyse the location of perforations in shells to make judgements about their use as symbolic objects (e.g., beads), the assumption being that holes attributable to deliberate human behaviour are more likely to exhibit low variability in their anatomical locations, while holes attributable to natural processes yield more random perforations. However, there are non-anthropogenic factors that can cause perforations in shells and these may not be random. The aim of the study is compare the variation in holes in shells from archaeological sites from the Old World with the variation of holes in shells pierced by mollusc predators. Methods Three hundred and sixteen scientific papers were retrieved from online databases by using keywords, (e.g., ‘shell beads’; ‘pierced shells’; ‘drilling predators’); 79 of these publications enabled us to conduct a systematic review to qualitatively assess the location of the holes in the shells described in the published articles. In turn, 54 publications were used to assess the location of the holes in the shells made by non-human predators. Results Almost all archaeological sites described shells with holes in a variety of anatomical locations. High variation of hole-placement was found within the same species from the same site, as well as among sites. These results contrast with research on predatory molluscs, which tend to be more specific in where they attacked their prey. Gastropod and bivalve predators choose similar hole locations to humans. Discussion Based on figures in the analysed articles, variation in hole-location on pierced shells from archaeological sites was similar to variation in the placement of holes created by non-human animals. Importantly, we found that some predators choose similar hole locations to humans. We discuss these findings and identify factors researchers might want to consider when interpreting shells recovered from archaeological contexts. PMID:28123913

HPV Vaccine Effective at Multiple Anatomic Sites

Cancer.gov

A new study from NCI researchers finds that the HPV vaccine protects young women from infection with high-risk HPV types at the three primary anatomic sites where persistent HPV infections can cause cancer. The multi-site protection also was observed at l

Construction of a 3-D anatomical model for teaching temporal lobectomy.

PubMed

de Ribaupierre, Sandrine; Wilson, Timothy D

2012-06-01

Although we live and work in 3 dimensional space, most of the anatomical teaching during medical school is done on 2-D (books, TV and computer screens, etc). 3-D spatial abilities are essential for a surgeon but teaching spatial skills in a non-threatening and safe educational environment is a much more difficult pedagogical task. Currently, initial anatomical knowledge formation or specific surgical anatomy techniques, are taught either in the OR itself, or in cadaveric labs; which means that the trainee has only limited exposure. 3-D computer models incorporated into virtual learning environments may provide an intermediate and key step in a blended learning approach for spatially challenging anatomical knowledge formation. Specific anatomical structures and their spatial orientation can be further clinically contextualized through demonstrations of surgical procedures in the 3-D digital environments. Recordings of digital models enable learner reviews, taking as much time as they want, stopping the demonstration, and/or exploring the model to understand the anatomical relation of each structure. We present here how a temporal lobectomy virtual model has been developed to aid residents and fellows conceptualization of the anatomical relationships between different cerebral structures during that procedure. We suggest in comparison to cadaveric dissection, such virtual models represent a cost effective pedagogical methodology providing excellent support for anatomical learning and surgical technique training. Copyright © 2012 Elsevier Ltd. All rights reserved.

The Influence of Knee Flexion Angle for Graft Fixation on Rotational Knee Stability During Anterior Cruciate Ligament Reconstruction: A Biomechanical Study.

PubMed

Debandi, Aníbal; Maeyama, Akira; Hoshino, Yuichi; Asai, Shigehiro; Goto, Bunsei; Smolinski, Patrick; Fu, Freddie H

2016-11-01

To evaluate the effect of knee flexion angle for hamstring graft fixation, full extension (FE), or 30°, on acceleration of the knee motion during pivot-shift testing after either anatomic or nonanatomic anterior cruciate ligament (ACL) reconstruction using triaxial accelerometry. Two types of ACL reconstructions (anatomic and nonanatomic) using 2 different angles of knee flexion during graft fixation (FE and 30°) were performed on 12 fresh-frozen human knees making 4 groups: anatomic-FE, anatomic-30°, nonanatomic-FE, and nonanatomic-30°. Manual pivot-shift testing was performed at ACL-intact, ACL-deficient, and ACL-reconstructed conditions. Three-dimensional acceleration of knee motion was recorded using a triaxial accelerometer. The anatomic-30° group showed the smallest overall magnitude of acceleration among the ACL-reconstructed groups (P = .0039). There were no significant differences among the anatomic-FE group, the nonanatomic-FE group, and the nonantomic-30° group (anatomic-FE vs nonanatomic-FE, P = .1093; anatomic-FE vs nonanatomic-30°, P = .8728; and nonanatomic-FE vs nonanatomic-30°, P = .1093). After ACL transection, acceleration was reduced by ACL reconstruction with the exception of the nonanatomic-FE group that did not show a significant difference when compared with the ACL-deficient (P = .4537). The anatomic ACL reconstruction with the graft fixed at 30° of knee flexion better restored rotational knee stability compared with FE. An ACL graft fixed with the knee at FE in anatomic position did not show a significant difference compared with the nonanatomic ACL reconstructions. Knee flexion angle at the time of graft fixation for ACL reconstruction can be considered to maximize the rotational knee stability. Copyright © 2016 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Most of the extant mtDNA boundaries in South and Southwest Asia were likely shaped during the initial settlement of Eurasia by anatomically modern humans

PubMed Central

Metspalu, Mait; Kivisild, Toomas; Metspalu, Ene; Parik, Jüri; Hudjashov, Georgi; Kaldma, Katrin; Serk, Piia; Karmin, Monika; Behar, Doron M; Gilbert, M Thomas P; Endicott, Phillip; Mastana, Sarabjit; Papiha, Surinder S; Skorecki, Karl; Torroni, Antonio; Villems, Richard

2004-01-01

Background Recent advances in the understanding of the maternal and paternal heritage of south and southwest Asian populations have highlighted their role in the colonization of Eurasia by anatomically modern humans. Further understanding requires a deeper insight into the topology of the branches of the Indian mtDNA phylogenetic tree, which should be contextualized within the phylogeography of the neighboring regional mtDNA variation. Accordingly, we have analyzed mtDNA control and coding region variation in 796 Indian (including both tribal and caste populations from different parts of India) and 436 Iranian mtDNAs. The results were integrated and analyzed together with published data from South, Southeast Asia and West Eurasia. Results Four new Indian-specific haplogroup M sub-clades were defined. These, in combination with two previously described haplogroups, encompass approximately one third of the haplogroup M mtDNAs in India. Their phylogeography and spread among different linguistic phyla and social strata was investigated in detail. Furthermore, the analysis of the Iranian mtDNA pool revealed patterns of limited reciprocal gene flow between Iran and the Indian sub-continent and allowed the identification of different assemblies of shared mtDNA sub-clades. Conclusions Since the initial peopling of South and West Asia by anatomically modern humans, when this region may well have provided the initial settlers who colonized much of the rest of Eurasia, the gene flow in and out of India of the maternally transmitted mtDNA has been surprisingly limited. Specifically, our analysis of the mtDNA haplogroups, which are shared between Indian and Iranian populations and exhibit coalescence ages corresponding to around the early Upper Paleolithic, indicates that they are present in India largely as Indian-specific sub-lineages. In contrast, other ancient Indian-specific variants of M and R are very rare outside the sub-continent. PMID:15339343

Anatomical feasibility study of flexor hallucis longus transfer in treatment of Achilles tendon and posteromedial portal of ankle arthroscopy.

PubMed

Mao, Haijiao; Wang, Linger; Dong, Wenwei; Liu, Zhenxin; Yin, Weigang; Xu, Dachuan; Wapner, Keith L

2018-04-16

The aim of this study was to evaluate the occurrence of anatomical variations of the musculotendinous junction of the flexor hallucis longus (FHL) muscle, the relationship between FHL tendon or muscle and the tibial neurovascular bundle at the level of the posterior ankle joint in human cadavers. Seventy embalmed feet from 20 male and 15 female cadavers, the cadavers' mean age was 65.4 (range from 14 to 82) years, were dissected and anatomically classified to observe FHL muscle morphology define the relationship between FHL tendon or muscle and the tibial neurovascular bundle. The distance between the musculotendinous junction and the relationship between FHL tendon or muscle and the tibial neurovascular bundle was determined. Three morphology types of FHL muscle were identified: a long lateral and shorter medial muscle belly, which was observed in 63 specimens (90%); equal length medial and lateral muscle bellies, this variant was only observed in five specimens (7.1%); one lateral and no medial muscle belly, which was observed in two specimens (2.9%). No statistically significant difference was observed according to gender or side (p > 0.05). Two patterns were identified and described between FHL tendon or muscle and the tibial neurovascular bundle. Pattern 1, the distance between the neurovascular bundle and FHL tendon was 3.46 mm (range 2.34-8.84, SD = 2.12) which was observed in 66 specimens (94.3%); Pattern 2, there was no distance which was observed in four specimens (5.7%). Knowing FHL muscle morphology, variations provide new important insights into secure planning and execution of a FHL transfer for Achilles tendon defect as well as for the interpretation of ultrasound and magnetic resonance images. With posterior arthroscopic for the treatment of various ankle pathologies, posteromedial portal may be introduced into the posterior aspect of the ankle without gross injury to the tibial neurovascular structures because of the gap between the neurovascular bundle and FHL tendon.

Anatomical variations of the deep head of Cruveilhier of the flexor pollicis brevis and its significance for the evolution of the precision grip.

PubMed

Dunlap, Samuel S; Aziz, M Ashraf; Ziermann, Janine M

2017-01-01

Cruveilhier described in 1834 the human flexor pollicis brevis (FPB), a muscle of the thenar compartment, as having a superficial and a deep head, respectively, inserted onto the radial and ulnar sesamoids of the thumb. Since then, Cruveilhier's deep head has been controversially discussed. Often this deep head is confused with Henle's "interosseous palmaris volaris" or said to be a slip of the oblique adductor pollicis. In the 1960s, Day and Napier described anatomical variations of the insertions of Cruveilhier's deep head, including its absence, and hypothesized, that the shift of the deep head's insertion from ulnar to radial facilitated "true opposability" in anthropoids. Their general thesis for muscular arrangements underlying the power and precision grip is sound, but they did not delineate their deep head from Henle's muscle or the adductor pollicis, and their description of the attachments of Cruveilhier's deep head were too vague and not supported by a significant portion of the anatomical literature. Here, we reinvestigated Cruveilhier's deep head to resolve the controversy about it and because many newer anatomy textbooks do not describe this muscle, while it is often an obvious functionally (writing, texting, precision grip) and clinically significant thenar muscle. For the first time, we empirically delineated Cruveilhier's deep head from neighboring muscles with which it was previously confused. We observed 100% occurrence of the uncontested deep head in 80 human hands, displaying a similar variability of insertions as Day and Napier, but in significantly different numbers. Furthermore, we found variability in the origin and included as important landmarks the trapezoid and the ligamentum carpi radiatum. We tested the assertion regarding the evolutionary morphology and its role in the improvements in thumb movements during various precision grips. Our overall conclusions differ with respect to the developmental and evolutionary origin of the FPB heads.

Anatomical brain images alone can accurately diagnose chronic neuropsychiatric illnesses.

PubMed

Bansal, Ravi; Staib, Lawrence H; Laine, Andrew F; Hao, Xuejun; Xu, Dongrong; Liu, Jun; Weissman, Myrna; Peterson, Bradley S

2012-01-01

Diagnoses using imaging-based measures alone offer the hope of improving the accuracy of clinical diagnosis, thereby reducing the costs associated with incorrect treatments. Previous attempts to use brain imaging for diagnosis, however, have had only limited success in diagnosing patients who are independent of the samples used to derive the diagnostic algorithms. We aimed to develop a classification algorithm that can accurately diagnose chronic, well-characterized neuropsychiatric illness in single individuals, given the availability of sufficiently precise delineations of brain regions across several neural systems in anatomical MR images of the brain. We have developed an automated method to diagnose individuals as having one of various neuropsychiatric illnesses using only anatomical MRI scans. The method employs a semi-supervised learning algorithm that discovers natural groupings of brains based on the spatial patterns of variation in the morphology of the cerebral cortex and other brain regions. We used split-half and leave-one-out cross-validation analyses in large MRI datasets to assess the reproducibility and diagnostic accuracy of those groupings. In MRI datasets from persons with Attention-Deficit/Hyperactivity Disorder, Schizophrenia, Tourette Syndrome, Bipolar Disorder, or persons at high or low familial risk for Major Depressive Disorder, our method discriminated with high specificity and nearly perfect sensitivity the brains of persons who had one specific neuropsychiatric disorder from the brains of healthy participants and the brains of persons who had a different neuropsychiatric disorder. Although the classification algorithm presupposes the availability of precisely delineated brain regions, our findings suggest that patterns of morphological variation across brain surfaces, extracted from MRI scans alone, can successfully diagnose the presence of chronic neuropsychiatric disorders. Extensions of these methods are likely to provide biomarkers that will aid in identifying biological subtypes of those disorders, predicting disease course, and individualizing treatments for a wide range of neuropsychiatric illnesses.

Delineation of the primary tumour Clinical Target Volumes (CTV-P) in laryngeal, hypopharyngeal, oropharyngeal and oral cavity squamous cell carcinoma: AIRO, CACA, DAHANCA, EORTC, GEORCC, GORTEC, HKNPCSG, HNCIG, IAG-KHT, LPRHHT, NCIC CTG, NCRI, NRG Oncology, PHNS, SBRT, SOMERA, SRO, SSHNO, TROG consensus guidelines.

PubMed

Grégoire, Vincent; Evans, Mererid; Le, Quynh-Thu; Bourhis, Jean; Budach, Volker; Chen, Amy; Eisbruch, Abraham; Feng, Mei; Giralt, Jordi; Gupta, Tejpal; Hamoir, Marc; Helito, Juliana K; Hu, Chaosu; Hunter, Keith; Johansen, Jorgen; Kaanders, Johannes; Laskar, Sarbani Ghosh; Lee, Anne; Maingon, Philippe; Mäkitie, Antti; Micciche', Francesco; Nicolai, Piero; O'Sullivan, Brian; Poitevin, Adela; Porceddu, Sandro; Składowski, Krzysztof; Tribius, Silke; Waldron, John; Wee, Joseph; Yao, Min; Yom, Sue S; Zimmermann, Frank; Grau, Cai

2018-01-01

Few studies have reported large inter-observer variations in target volume selection and delineation in patients treated with radiotherapy for head and neck squamous cell carcinoma. Consensus guidelines have been published for the neck nodes (see Grégoire et al., 2003, 2014), but such recommendations are lacking for primary tumour delineation. For the latter, two main schools of thoughts are prevailing, one based on geometric expansion of the Gross Tumour Volume (GTV) as promoted by DAHANCA, and the other one based on anatomical expansion of the GTV using compartmentalization of head and neck anatomy. For each anatomic location within the larynx, hypopharynx, oropharynx and oral cavity, and for each T-stage, the DAHANCA proposal has been comprehensively reviewed and edited to include anatomic knowledge into the geometric Clinical Target Volume (CTV) delineation concept. A first proposal was put forward by the leading authors of this publication (VG and CG) and discussed with opinion leaders in head and neck radiation oncology from Europe, Asia, Australia/New Zealand, North America and South America to reach a worldwide consensus. This consensus proposes two CTVs for the primary tumour, the so called CTV-P1 and CVT-P2, corresponding to a high and lower tumour burden, and which should be associated with a high and a lower dose prescription, respectively. Implementation of these guidelines in the daily practice of radiation oncology should contribute to reduce treatment variations from clinicians to clinicians, facilitate the conduct of multi-institutional clinical trials, and contribute to improved care of patients with head and neck carcinoma. Copyright © 2017 Elsevier B.V. All rights reserved.

Anatomical variations of the deep head of Cruveilhier of the flexor pollicis brevis and its significance for the evolution of the precision grip

PubMed Central

Aziz, M. Ashraf

2017-01-01

Cruveilhier described in 1834 the human flexor pollicis brevis (FPB), a muscle of the thenar compartment, as having a superficial and a deep head, respectively, inserted onto the radial and ulnar sesamoids of the thumb. Since then, Cruveilhier’s deep head has been controversially discussed. Often this deep head is confused with Henle’s “interosseous palmaris volaris” or said to be a slip of the oblique adductor pollicis. In the 1960s, Day and Napier described anatomical variations of the insertions of Cruveilhier’s deep head, including its absence, and hypothesized, that the shift of the deep head’s insertion from ulnar to radial facilitated “true opposability” in anthropoids. Their general thesis for muscular arrangements underlying the power and precision grip is sound, but they did not delineate their deep head from Henle’s muscle or the adductor pollicis, and their description of the attachments of Cruveilhier’s deep head were too vague and not supported by a significant portion of the anatomical literature. Here, we reinvestigated Cruveilhier’s deep head to resolve the controversy about it and because many newer anatomy textbooks do not describe this muscle, while it is often an obvious functionally (writing, texting, precision grip) and clinically significant thenar muscle. For the first time, we empirically delineated Cruveilhier’s deep head from neighboring muscles with which it was previously confused. We observed 100% occurrence of the uncontested deep head in 80 human hands, displaying a similar variability of insertions as Day and Napier, but in significantly different numbers. Furthermore, we found variability in the origin and included as important landmarks the trapezoid and the ligamentum carpi radiatum. We tested the assertion regarding the evolutionary morphology and its role in the improvements in thumb movements during various precision grips. Our overall conclusions differ with respect to the developmental and evolutionary origin of the FPB heads. PMID:29121048

Anatomical Variability of the Posterior Communicating Artery

PubMed Central

Gunnal, Sandhya Arvind; Farooqui, Mujibuddin S.; Wabale, Rajendra N.

2018-01-01

Objective: Although posterior communicating artery (PCoA) is a smaller branch of the internal carotid artery, it gives the main contribution in the formation of circle of Willis (CW) by communicating with the internal carotid arterial system and the vertebro-basilar arterial system. The size of PCoA varies frequently. The present work aims to study the PCoA regarding its morphology, morphometry, and symmetry. Materials and Methods: This study was conducted on 170 human cadaveric brains. Brains were dissected carefully and delicately to expose all components of CW, especially PCoA. Morphological variations of PCoA were noted along with its morphometry and symmetry. Results: Morphological variations of PCoA were aplasia (3.52%), hypoplasia (25.29%), fenestration (0.58%), and persistent fetal pattern (16.47%). In the present study, we found the five different types of terminations of PCoA. Type I termination was the most common type, seen in 92.94% of cases, Type II termination was seen in 1.17%, Type III and Type IV terminations both were seen in 0.58%, and Type V was seen in 1.17%. The mean length of PCoA was 15.9 mm and 15.3 mm on the right and left sides, respectively. The mean diameter of PCoA was 2.1 mm and 1.9 mm on the right and left sides, respectively. Symmetry of PCoA was seen in 65.29% and asymmetric PCoA was seen in 34.70% of cases. Conclusion: The present study provides the complete description of PCoA regarding its morphology, symmetry, and morphometry. Awareness of these anatomical variations is important in neurovascular procedures. PMID:29682035

Color Doppler Sonographic and Cadaveric Study of the Arterial Vascularity of the Lateral Upper Arm Flap.

PubMed

Sun, Ruimei; Ding, Yu; Sun, Chuanzheng; Li, Xiaojiang; Wang, Jinde; Li, Lei; Yang, Jie; Ren, Yanxin; Zhong, Zhaoming

2016-04-01

To determine the importance of adequate preoperative assessment with color Doppler sonography to assist in the successful transfer of lateral upper arm flaps by studying the lateral upper arm flap with color Doppler sonography and analyzing the anatomic features of the radial collateral artery. A clinical case-control study was performed. The radial collateral artery was studied with color Doppler sonography in 15 healthy volunteers. The origins, courses, variations, and locations of the perforators of the radial collateral artery were recorded. The results and data from the color Doppler sonographic investigation were compared with an anatomic study that was performed on 22 adult cadaveric upper limb specimens. The volunteer group (14 of 15 volunteers) and the cadaveric group (19 of 22 upper arm specimens) clearly showed that the branch pattern of the arterial supply was as follows: brachial artery → deep brachial artery → radial collateral artery → posterior radial collateral artery → myocutaneous perforator. Variations in the origin of the radial collateral artery were identified in 1 volunteer bilaterally and in 3 upper arm specimens. The diameters of the artery and vein measured at the distal insertion of the deltoid and the origin of the deep brachial artery were not significantly different between the volunteer and cadaver groups (P > .05). Due to the difference in measuring methods, the length of the vascular pedicles was significantly different between the groups (P < .05). Color Doppler sonography can facilitate the preoperative assessment of the origin, course, variations, and locations of the radial collateral artery and therefore may increase the success rate of lateral upper arm flap transfer. © 2016 by the American Institute of Ultrasound in Medicine.

Prostatic Artery Embolization for Enlarged Prostates Due to Benign Prostatic Hyperplasia. How I Do It

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carnevale, Francisco C., E-mail: fcarnevale@uol.com.br; Antunes, Alberto A., E-mail: antunesuro@uol.com.br

2013-12-15

Prostatic artery embolization (PAE) has emerged as an alternative to surgical treatments for benign prostatic hyperplasia (BPH). Patient selection and refined technique are essential for good results. Urodynamic evaluation and magnetic resonance imaging are very important and technical limitations are related to elderly patients with tortuous and atherosclerotic vessels, anatomical variations, difficulty visualizing and catheterizing small diameter arteries feeding the prostate, and the potential risk of bladder and rectum ischemia. The use of small-diameter hydrophilic microcatheters is mandatory. Patients can be treated safely by PAE with low rates of side effects, reducing prostate volume with clinical symptoms and quality ofmore » life improvement without urinary incontinence, ejaculatory disorders, or erectile dysfunction. A multidisciplinary approach with urologists and interventional radiologists is essential to achieve better results.« less

Efficacy of autologous platelets in macular hole surgery.

PubMed

Konstantinidis, Aristeidis; Hero, Mark; Nanos, Panagiotis; Panos, Georgios D

2013-01-01

The introduction of optical coherence tomography has allowed accurate measurement of the size of macular holes. A retrospective consecutive review was performed of 21 patients undergoing macular hole repair with vitrectomy, gas tamponade, and autologous platelet injection and we assessed the effect of macular hole parameters on anatomic and functional outcomes. We looked at the demographic features, final visual outcome, and anatomical closure. Twenty-one patients were included in the study. They underwent routine vitrectomy with gas tamponade (C3F8) and injection of autologous platelets. All patients were advised to maintain a facedown posture for 2 weeks. Anatomical closure was confirmed in all cases and 20 out of 21 of patients had improved postoperative visual acuity by two or more lines. In our series, the macular hole dimensions did not have much effect on the final results. The use of autologous platelets and strict facedown posture seems to be the deciding factor in good anatomical and visual outcome irrespective of macular hole dimensions.

Persistent trigeminal artery feeding a hemispheric branch of the posterior inferior cerebellar artery: a rare anatomic variant.

PubMed

Perot, G; Clarençon, F; Di Maria, F; Sourour, N; Biondi, A; Cornu, P; Chiras, J

2011-10-01

Persistent trigeminal artery is a rare persistent carotid-basilar anastomosis that usually connect the infracavernous segment of the ICA with the basilar artery. Rarely, PTA may feed cerebellar artery. We describe an exceptional case of PTA terminating in postero-inferior cerebellar artery (PICA) hemispheric branch. Angiographic and CTA features are presented and hypotheses regarding developmental origin of this variation are discussed. Copyright © 2011. Published by Elsevier Masson SAS.

Gross Anatomical Study of the Nerve Supply of Genitourinary Structures in Female Mongrel Hound Dogs

PubMed Central

Gomez-Amaya, S. M.; Ruggieri, M. R.; Arias Serrato, S. A.; Massicotte, V. S.; Barbe, M. F.

2014-01-01

Summary Anatomical variations in lumbosacral plexus or nerves to genitourinary structures in dogs are under described, despite their importance during surgery and potential contributions to neuromuscular syndromes. Gross dissection of 16 female mongrel hound dogs showed frequent variations in lumbosacral plexus classification, sympathetic ganglia, ventral rami input to nerves innervating genitourinary structures and pudendal nerve (PdN) branching. Lumbosacral plexus classification types were mixed, rather than pure, in 13 (82%) of dogs. The genitofemoral nerve (GFN) originated from ventral ramus of L4 in 67% of nerves, differing from the expected L3. Considerable variability was seen in ventral rami origins of pelvic (PN) and Pd nerves, with new findings of L7 contributions to PN, joining S1 and S2 input (23% of sides in 11 dogs) or S1–S3 input (5%), and to PdN, joining S1–S2, unilaterally, in one dog. L7 input was confirmed using retrograde dye tracing methods. The PN also received CG1 contributions, bilaterally, in one dog. The PdN branched unusually in two dogs. Lumbosacral sympathetic ganglia had variant intra-, inter- and multisegmental connectivity in 6 (38%). Thus, the anatomy of mongrel dogs had higher variability than previously described for purebred dogs. Knowledge of this variant innervation during surgery could aid in the preservation of nerves and reduce risk of urinary and sexual dysfunctions. PMID:24730986

A Review of the Comparative Anatomy, Histology, Physiology and Pathology of the Nasal Cavity of Rats, Mice, Dogs and Non-human Primates. Relevance to Inhalation Toxicology and Human Health Risk Assessment.

PubMed

Chamanza, R; Wright, J A

2015-11-01

There are many significant differences in the structural and functional anatomy of the nasal cavity of man and laboratory animals. Some of the differences may be responsible for the species-specific nasal lesions that are often observed in response to inhaled toxicants. This paper reviews the comparative anatomy, physiology and pathology of the nasal cavity of the rat, mouse, dog, monkey and man, highlighting factors that may influence the distribution of nasal lesions. Gross anatomical variations such as turbinate structure, folds or grooves on nasal walls, or presence or absence of accessory structures, may influence nasal airflow and species-specific uptake and deposition of inhaled material. In addition, interspecies variations in the morphological and biochemical composition and distribution of the nasal epithelium may affect the local tissue susceptibility and play a role in the development of species-specific nasal lesions. It is concluded that, while the nasal cavity of the monkey might be more similar to that of man, each laboratory animal species provides a model that responds in a characteristic and species-specific manner. Therefore for human risk assessment, careful consideration must be given to the anatomical differences between a given animal model and man. Copyright © 2015 Elsevier Ltd. All rights reserved.

Genetic evidence and the modern human origins debate.

PubMed

Relethford, J H

2008-06-01

A continued debate in anthropology concerns the evolutionary origin of 'anatomically modern humans' (Homo sapiens sapiens). Different models have been proposed to examine the related questions of (1) where and when anatomically modern humans first appeared and (2) the genetic and evolutionary relationship between modern humans and earlier human populations. Genetic data have been increasingly used to address these questions. Genetic data on living human populations have been used to reconstruct the evolutionary history of the human species by considering how global patterns of human variation could be produced given different evolutionary scenarios. Of particular interest are gene trees that reconstruct the time and place of the most recent common ancestor of humanity for a given haplotype and the analysis of regional differences in genetic diversity. Ancient DNA has also allowed a direct assessment of genetic variation in European Neandertals. Together with the fossil record, genetic data provide insight into the origin of modern humans. The evidence points to an African origin of modern humans dating back to 200,000 years followed by later expansions of moderns out of Africa across the Old World. What is less clear is what happened when these early modern humans met preexisting 'archaic human' populations outside of Africa. At present, it is difficult to distinguish between a model of total genetic replacement and a model that includes some degree of genetic mixture.

Echocardiographic Classification and Surgical Approaches to Double-Outlet Right Ventricle for Great Arteries Arising Almost Exclusively from the Right Ventricle.

PubMed

Pang, Kun-Jing; Meng, Hong; Hu, Sheng-Shou; Wang, Hao; Hsi, David; Hua, Zhong-Dong; Pan, Xiang-Bin; Li, Shou-Jun

2017-08-01

Selecting an appropriate surgical approach for double-outlet right ventricle (DORV), a complex congenital cardiac malformation with many anatomic variations, is difficult. Therefore, we determined the feasibility of using an echocardiographic classification system, which describes the anatomic variations in more precise terms than the current system does, to determine whether it could help direct surgical plans. Our system includes 8 DORV subtypes, categorized according to 3 factors: the relative positions of the great arteries (normal or abnormal), the relationship between the great arteries and the ventricular septal defect (committed or noncommitted), and the presence or absence of right ventricular outflow tract obstruction (RVOTO). Surgical approaches in 407 patients were based on their DORV subtype, as determined by echocardiography. We found that the optimal surgical management of patients classified as normal/committed/no RVOTO, normal/committed/RVOTO, and abnormal/committed/no RVOTO was, respectively, like that for patients with large ventricular septal defects, tetralogy of Fallot, and transposition of the great arteries without RVOTO. Patients with abnormal/committed/RVOTO anatomy and those with abnormal/noncommitted/RVOTO anatomy underwent intraventricular repair and double-root translocation. For patients with other types of DORV, choosing the appropriate surgical approach and biventricular repair techniques was more complex. We think that our classification system accurately groups DORV patients and enables surgeons to select the best approach for each patient's cardiac anatomy.

Brain organization of gorillas reflects species differences in ecology

PubMed Central

Barks, Sarah K.; Calhoun, Michael E.; Hopkins, William D.; Cranfield, Michael R.; Mudakikwa, Antoine; Stoinski, Tara S.; Patterson, Francine G.; Erwin, Joseph M.; Hecht, Erin E.; Hof, Patrick R.; Sherwood, Chet C.

2014-01-01

Gorillas include separate eastern (Gorilla beringei) and western (Gorilla gorilla) African species that diverged from each other approximately 2 million years ago. Although anatomical, genetic, behavioral, and socioecological differences have been noted among gorilla populations, little is known about variation in their brain structure. This study examines neuroanatomical variation between gorilla species using structural neuroimaging. Postmortem magnetic resonance images were obtained of brains from 18 captive western lowland gorillas (Gorilla gorilla gorilla), 15 wild mountain gorillas (Gorilla beringei beringei), and 3 Grauer's gorillas (Gorilla beringei graueri) (both wild and captive). Stereologic methods were used to measure volumes of brain structures, including left and right frontal lobe gray and white matter, temporal lobe gray and white matter, parietal and occipital lobes gray and white matter, insular gray matter, hippocampus, striatum, thalamus, each hemisphere and the vermis of the cerebellum, and the external and extreme capsules together with the claustrum. Among the species differences, the volumes of the hippocampus and cerebellum were significantly larger in G. gorilla than G. beringei. These anatomical differences may relate to divergent ecological adaptations of the two species. Specifically, G. gorilla engage in more arboreal locomotion and thus may rely more on cerebellar circuits. In addition, they tend to eat more fruit and have larger home ranges and consequently might depend more on spatial mapping functions of the hippocampus. PMID:25360547

Oval Window Size and Shape: a Micro-CT Anatomical Study With Considerations for Stapes Surgery.

PubMed

Zdilla, Matthew J; Skrzat, Janusz; Kozerska, Magdalena; Leszczyński, Bartosz; Tarasiuk, Jacek; Wroński, Sebastian

2018-06-01

The oval window is an important structure with regard to stapes surgeries, including stapedotomy for the treatment of otosclerosis. Recent study of perioperative imaging of the oval window has revealed that oval window niche height can indicate both operative difficulty and subjective discomfort during otosclerosis surgery. With regard to shape, structures incorporated into the oval window niche, such as cartilage grafts, must be compatible with the shape of the oval window. Despite the clinical importance of the oval window, there is little information regarding its size and shape. This study assessed oval window size and shape via micro-computed tomography paired with modern morphometric methodology in the fetal, infant, child, and adult populations. Additionally, the study compared oval window size and shape between sexes and between left- and right-sided ears. No significant differences were found among traditional morphometric parameters among age groups, sides, or sexes. However, geometric morphometric methods revealed shape differences between age groups. Further, geometric morphometric methods provided the average oval window shape and most-likely shape variance. Beyond demonstrating oval window size and shape variation, the results of this report will aid in identifying patients among whom anatomical variation may contribute to surgical difficulty and surgeon discomfort, or otherwise warrant preoperative adaptations for the incorporation of materials into and around the oval window.

Brain organization of gorillas reflects species differences in ecology.

PubMed

Barks, Sarah K; Calhoun, Michael E; Hopkins, William D; Cranfield, Michael R; Mudakikwa, Antoine; Stoinski, Tara S; Patterson, Francine G; Erwin, Joseph M; Hecht, Erin E; Hof, Patrick R; Sherwood, Chet C

2015-02-01

Gorillas include separate eastern (Gorilla beringei) and western (Gorilla gorilla) African species that diverged from each other approximately 2 million years ago. Although anatomical, genetic, behavioral, and socioecological differences have been noted among gorilla populations, little is known about variation in their brain structure. This study examines neuroanatomical variation between gorilla species using structural neuroimaging. Postmortem magnetic resonance images were obtained of brains from 18 captive western lowland gorillas (Gorilla gorilla gorilla), 15 wild mountain gorillas (Gorilla beringei beringei), and 3 Grauer's gorillas (Gorilla beringei graueri) (both wild and captive). Stereologic methods were used to measure volumes of brain structures, including left and right frontal lobe gray and white matter, temporal lobe gray and white matter, parietal and occipital lobes gray and white matter, insular gray matter, hippocampus, striatum, thalamus, each hemisphere and the vermis of the cerebellum, and the external and extreme capsules together with the claustrum. Among the species differences, the volumes of the hippocampus and cerebellum were significantly larger in G. gorilla than G. beringei. These anatomical differences may relate to divergent ecological adaptations of the two species. Specifically, G. gorilla engages in more arboreal locomotion and thus may rely more on cerebellar circuits. In addition, they tend to eat more fruit and have larger home ranges and consequently might depend more on spatial mapping functions of the hippocampus. © 2015 Wiley Periodicals, Inc.

Anatomical location of metastatic lymph nodes: an indispensable prognostic factor for gastric cancer patients who underwent curative resection.

PubMed

Zhao, Bochao; Zhang, Jingting; Zhang, Jiale; Chen, Xiuxiu; Chen, Junqing; Wang, Zhenning; Xu, Huimian; Huang, Baojun

2018-02-01

Although the numeric-based lymph node (LN) staging was widely used in the worldwide, it did not represent the anatomical location of metastatic lymph nodes (MLNs) and not reflect extent of LN dissection. Therefore, in the present study, we investigated whether the anatomical location of MLNs was still necessary to evaluate the prognosis of node-positive gastric cancer (GC) patients. We reviewed 1451 GC patients who underwent radical gastrectomy in our institution between January 1986 and January 2008. All patients were reclassified into several groups according to the anatomical location of MLNs and the number of MLNs. The prognostic differences between different patient groups were compared and clinicopathologic features were analyzed. In the present study, both anatomical location of MLNs and the number of MLNs were identified as the independent prognostic factors (p < .01). The patients with extraperigastric LN involvement showed a poorer prognosis compared with the perigastric-only group (p < .001). For the N1-N2 stage patients, the prognostic discrepancy was still observed among them when the anatomical location of MLNs was considered (p < .05). For the N3-stage patients, although the anatomical location of MLNs had no significant effect on the prognosis of these patients, the higher number of MLNs in the extraperigastric area was correlated with the unfavorable prognosis (p < .05). The anatomical location of MLNs was an important factor influencing the prognostic outcome of GC patients. To provide more accurate prognostic information for GC patients, the anatomical location of MLNs should not be ignored.

A New Anatomic Variation: Coexistence of Both Dandy-Walker Variant and Ophthalmic Artery Originating From Contralateral Internal Carotid Artery.

PubMed

Ogul, Hayri; Havan, Nuri; Gedikli, Yusuf; Pirimoglu, Berhan; Kantarci, Mecit

2016-06-01

The authors report on 1 patient of variant origin of right ophthalmic artery (OA) from ophthalmic segment of the left internal carotid artery. A 41-year-old man was performed magnetic resonance (MR) imaging and MR angiography. Cerebral MR imaging revealed a Dandy-Walker variant. In MR angiography the authors observed this unusual variant of origin of OA and a complete occlusion of right internal carotid artery. To the authors' knowledge, this is the first patient who has coincidence of both Dandy-Walker variant and origin of OA from contralateral internal carotid artery. Careful observation of MR angiography images with maximum intensity projection is very important for detecting rare vascular variations.

Foot deformities in Renaissance paintings. A mystery of symbolism, artistic licence, illusion and true representation in five renowned Renaissance painters.

PubMed

Lazzeri, D; Castello, M F; Grassetti, L; Dashti, T; Zhang, Y X; Persichetti, P

2015-01-01

Although Renaissance artists were skilled in representing normal anatomy, a close look at some paintings reveals anatomical variations in the depiction of the feet of human figures. A systematic review has identified 25 paintings by five artists in which the presumptive medico-artistic diagnosis of congenital or acquired foot deformity seems to be varyingly present. The connection between these five painters and what factors have influenced artists' style in the depiction of such deformities is discussed. The possible iconography and medical-historical meaning of such variations, as well as the possibility of artistic licence and real representation that drove the painters to depict these deformities, is explored and debated.

Uniting Tricholoma sulphureum and T. bufonium.

PubMed

Comandini, Ornella; Haug, Ingeborg; Rinaldi, Andrea C; Kuyper, Thomas W

2004-10-01

The taxonomic status and relationship of Tricholoma sulphureum and the similar T. bufonium were investigated using different sets of characters. These included morphological data on fruit bodies, ecological and chorological data, and analysis of the sequence data obtained for the ITS of basidiomes of different ecological and geographic origin. Moreover, the ectomycorrhizas formed by T. bufonium on Abies alba and Quercus sp. were characterised, and anatomical features compared with those of T. sulphureum mycorrhizas on coniferous and broad-leaved host trees. Our results revealed extensive ITS variation in members of the T. sulphureum group, but this variation was not correlated with morphology, ecology, or geographical distribution. We conclude that T. bufonium cannot be maintained as an autonomous taxon and should be treated as an infraspecific variant of T. sulphureum.

A Computational Model Quantifies the Effect of Anatomical Variability on Velopharyngeal Function

PubMed Central

Inouye, Joshua M.; Perry, Jamie L.; Lin, Kant Y.

2015-01-01

Purpose This study predicted the effects of velopharyngeal (VP) anatomical parameters on VP function to provide a greater understanding of speech mechanics and aid in the treatment of speech disorders. Method We created a computational model of the VP mechanism using dimensions obtained from magnetic resonance imaging measurements of 10 healthy adults. The model components included the levator veli palatini (LVP), the velum, and the posterior pharyngeal wall, and the simulations were based on material parameters from the literature. The outcome metrics were the VP closure force and LVP muscle activation required to achieve VP closure. Results Our average model compared favorably with experimental data from the literature. Simulations of 1,000 random anatomies reflected the large variability in closure forces observed experimentally. VP distance had the greatest effect on both outcome metrics when considering the observed anatomic variability. Other anatomical parameters were ranked by their predicted influences on the outcome metrics. Conclusions Our results support the implication that interventions for VP dysfunction that decrease anterior to posterior VP portal distance, increase velar length, and/or increase LVP cross-sectional area may be very effective. Future modeling studies will help to further our understanding of speech mechanics and optimize treatment of speech disorders. PMID:26049120

Endoscopy and polyps-diagnostic and therapeutic advances in management

PubMed Central

Steele, Scott R; Johnson, Eric K; Champagne, Bradley; Davis, Brad; Lee, Sang; Rivadeneira, David; Ross, Howard; Hayden, Dana A; Maykel, Justin A

2013-01-01

Despite multiple efforts aimed at early detection through screening, colon cancer remains the third leading cause of cancer-related deaths in the United States, with an estimated 51000 deaths during 2013 alone. The goal remains to identify and remove benign neoplastic polyps prior to becoming invasive cancers. Polypoid lesions of the colon vary widely from hyperplastic, hamartomatous and inflammatory to neoplastic adenomatous growths. Although these lesions are all benign, they are common, with up to one-quarter of patients over 60 years old will develop pre-malignant adenomatous polyps. Colonoscopy is the most effective screening tool to detect polyps and colon cancer, although several studies have demonstrated missed polyp rates from 6%-29%, largely due to variations in polyp size. This number can be as high as 40%, even with advanced (> 1 cm) adenomas. Other factors including sub-optimal bowel preparation, experience of the endoscopist, and patient anatomical variations all affect the detection rate. Additional challenges in decision-making exist when dealing with more advanced, and typically larger, polyps that have traditionally required formal resection. In this brief review, we will explore the recent advances in polyp detection and therapeutic options. PMID:23885138

Management of stones in childhood.

PubMed

Thomas, Ben G

2010-03-01

The purpose of this review was to report on the latest world literature relating to paediatric stone disease. Inevitably, because of the small numbers, the literature is limited and consists mainly of case series from individual centres. There is also a wide variation in criteria and techniques, making direct comparison limited. Changes in the incidence of stone disease are becoming more apparent particularly in female patients. Metabolic abnormalities can be identified in the majority of children with stones, and even in the absence of obvious physical stone, if detected warrant further follow-up. Data supporting the safety and efficacy of treatments for stones in children is improving constantly, but choosing the best option may be difficult on current evidence. Better long-term follow-up is still needed regarding adverse effects of treatment. A high index of suspicion is required for the diagnosis of stone disease in children, especially in the very young. After exclusion of anatomical abnormalities, metabolic evaluation is important in management and prevention of recurrence. Modalities for treatment are expanding all the time, but due to overall small numbers, and variations in the availability of technology, consensus views about treatment are difficult to agree.

TU-F-CAMPUS-I-01: Investigation of the Effective Dose From Bolus Tracking Acquisitions at Different Anatomical Locations in the Chest for CT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nowik, P; Bujila, R; Merzan, D

2015-06-15

Purpose: Stationary table acquisitions (Bolus tracking) in X-ray Computed Tomography (CT) can Result in dose length products (DLP) comparable to spiral scans. It is today unclear whether or not the effective dose (E) for Bolus Tracking can be approximated using target region specific conversion factors (E/DLP). The purpose of this study was to investigate how E depends on the anatomical location of the Bolus Tracking in relation to Chest CT scans with the same DLP. Methods: Effective doses were approximated for the ICRP 110 adult Reference Male (AM) and adult Reference Female (FM) computational voxel phantoms using software for CTmore » dose approximations (pre-simulated MC data). The effective dose was first approximated for a Chest CT scan using spiral technique and a CTDIvol (32 cm) of 6 mGy. The effective dose from the spiral scan was then compared to E approximated for contiguous Bolus Tracking acquisitions (1 cm separation), with a total collimation of 1 cm, over different locations of the chest of the voxel phantoms. The number of rotations used for the Bolus Tracking acquisitions was adjusted to yield the same DLP (32 cm) as the spiral scan. Results: Depending on the anatomical location of the Bolus Tracking, E ranged by factors of 1.3 to 6.8 for the AM phantom and 1.4 to 3.3 for the AF phantom, compared to the effective dose of the spiral scans. The greatest E for the Bolus Tracking acquisitions was observed for anatomical locations coinciding with breast tissue. This can be expected as breast tissue has a high tissue weighting factor in the calculation of E. Conclusion: For Chest CT scans, the effective dose from Bolus Tracking is highly dependent on the anatomical location where the scan is administered and will not always accurately be represented using target region specific conversion factors.« less

Lead tolerance of water hyacinth (Eichhornia crassipes Mart. - Pontederiaceae) as defined by anatomical and physiological traits.

PubMed

Pereira, Fabricio J; Castro, Evaristo M de; Oliveira, Cynthia de; Pires, Marinês F; Pereira, Marcio P; Ramos, Silvio J; Faquin, Valdemar

2014-09-01

This study aimed at verifying the lead tolerance of water hyacinth and at looking at consequent anatomical and physiological modifications. Water hyacinth plants were grown on nutrient solutions with five different lead concentrations: 0.00, 0.50, 1.00, 2.00 and 4.00 mg L-1 by 20 days. Photosynthesis, transpiration, stomatal conductance and the Ci/Ca rate were measured at the end of 15 days of experiment. At the end of the experiment, the anatomical modifications in the roots and leaves, and the activity of antioxidant system enzymes, were evaluated. Photosynthetic and Ci/Ca rates were both increased under all lead treatments. Leaf anatomy did not exhibit any evidence of toxicity effects, but showed modifications of the stomata and in the thickness of the palisade and spongy parenchyma in the presence of lead. Likewise, root anatomy did not exhibit any toxicity effects, but the xylem and phloem exhibited favorable modifications as well as increased apoplastic barriers. All antioxidant system enzymes exhibited increased activity in the leaves, and some modifications in roots, in the presence of lead. It is likely, therefore, that water hyacinth tolerance to lead is related to anatomical and physiological modifications such as increased photosynthesis and enhanced anatomical capacity for CO2 assimilation and water conductance.

Do item-writing flaws reduce examinations psychometric quality?

PubMed

Pais, João; Silva, Artur; Guimarães, Bruno; Povo, Ana; Coelho, Elisabete; Silva-Pereira, Fernanda; Lourinho, Isabel; Ferreira, Maria Amélia; Severo, Milton

2016-08-11

The psychometric characteristics of multiple-choice questions (MCQ) changed when taking into account their anatomical sites and the presence of item-writing flaws (IWF). The aim is to understand the impact of the anatomical sites and the presence of IWF in the psychometric qualities of the MCQ. 800 Clinical Anatomy MCQ from eight examinations were classified as standard or flawed items and according to one of the eight anatomical sites. An item was classified as flawed if it violated at least one of the principles of item writing. The difficulty and discrimination indices of each item were obtained. 55.8 % of the MCQ were flawed items. The anatomical site of the items explained 6.2 and 3.2 % of the difficulty and discrimination parameters and the IWF explained 2.8 and 0.8 %, respectively. The impact of the IWF was heterogeneous, the Writing the Stem and Writing the Choices categories had a negative impact (higher difficulty and lower discrimination) while the other categories did not have any impact. The anatomical site effect was higher than IWF effect in the psychometric characteristics of the examination. When constructing MCQ, the focus should be in the topic/area of the items and only after in the presence of IWF.

Functional anatomy of the caudal thoracolumbar and lumbosacral spine in the horse.

PubMed

Stubbs, N C; Hodges, P W; Jeffcott, L B; Cowin, G; Hodgson, D R; McGowan, C M

2006-08-01

Research in spinal biomechanics and functional anatomy has advanced back pain research in man. Yet, despite the performance limiting nature of back pain in horses, there are few data for the equine spine. To describe aspects of functional anatomy of the equine thoracolumbar and lumbosacral (LS) spine and potential effects on performance. The first study investigated variations in LS vertebral formula by post mortem examination of 120 horses. Midline vertebral transection was carried out on 65 Thoroughbred (TB), 24 Standardbred (SB) and 31 other breeds. The second study investigated morphology and biomechanics of the deep stabilising epaxial muscles of 13 horses using MRI (n = 3), anatomical dissection (n = 11) and biomechanical analysis (n = 6). The spinous process angular orientation relative to the vertebral body, was analysed at vertebrae T13, T18, L3, L5, L6 and S1. LS variations were found in 33.3% of the total group, 40.0% TB and 45.2% others, but 0% SB. Sacralisation of lumbar vertebra (L) 6 with LS motion between L5 and L6 occurred in 32.3% TB and 29.0% others. Five segmental multifidus fascicles were identified originating from spinous processes and vertebral laminae running craniocaudally onto the mammillary processes and lateral border of the sacrum, crossing between 1-5 intervertebral discs. Sacrocaudalis dorsalis (SCD) lateralis muscle was an extension of multifidus from L4, L5 and L6 depending on the vertebral formula whereas SCD medialis mm originated from S3. Both inserted on caudal vertebrae. Based on the location and direction of fibres, the principal action of the deep epaxial muscles was dorsoventral sagittal rotation. This action was dependent on vertebral spinous process/body orientation. We hypothesise that equine multifidus and SCD lateralis muscles act as caudal sagittal rotators of their vertebra of origin, as is the case in man, allowing dynamic stabilisation during dorsoventral motion. Equine multifidus anatomy and function are comparable to that of man. The high prevalence of anatomical variations in the LS spine may affect maximal dorsoventral motion, the stability of the LS joint and, therefore, have consequences for athletic performance. Further studies of these structures are warranted in appropriately selected poorly performing horses.

Anatomical masking of pressure footprints based on the Oxford Foot Model: validation and clinical relevance.

PubMed

Giacomozzi, Claudia; Stebbins, Julie A

2017-03-01

Plantar pressure analysis is widely used in the assessment of foot function. In order to assess regional loading, a mask is applied to the footprint to sub-divide it into regions of interest (ROIs). The most common masking method is based on geometric features of the footprint (GM). Footprint masking based on anatomical landmarks of the foot has been implemented more recently, and involves the integration of a 3D motion capture system, plantar pressure measurement device, and a multi-segment foot model. However, thorough validation of anatomical masking (AM) using pathological footprints has not yet been presented. In the present study, an AM method based on the Oxford Foot Model (OFM) was compared to an equivalent GM. Pressure footprints from 20 young healthy subjects (HG) and 20 patients with clubfoot (CF) were anatomically divided into 5 ROIs using a subset of the OFM markers. The same foot regions were also identified by using a standard GM method. Comparisons of intra-subject coefficient of variation (CV) showed that the OFM-based AM was at least as reliable as the GM for all investigated pressure parameters in all foot regions. Clinical relevance of AM was investigated by comparing footprints from HG and CF groups. Contact time, maximum force, force-time integral and contact area proved to be sensitive parameters that were able to distinguish HG and CF groups, using both AM and GM methods However, the AM method revealed statistically significant differences between groups in 75% of measured variables, compared to 62% using a standard GM method, indicating that the AM method is more sensitive for revealing differences between groups. Copyright © 2017 Elsevier B.V. All rights reserved.

Human Lumbar Ligamentum Flavum Anatomy for Epidural Anesthesia: Reviewing a 3D MR-Based Interactive Model and Postmortem Samples.

PubMed

Reina, Miguel A; Lirk, Philipp; Puigdellívol-Sánchez, Anna; Mavar, Marija; Prats-Galino, Alberto

2016-03-01

The ligamentum flavum (LF) forms the anatomic basis for the loss-of-resistance technique essential to the performance of epidural anesthesia. However, the LF presents considerable interindividual variability, including the possibility of midline gaps, which may influence the performance of epidural anesthesia. We devise a method to reconstruct the anatomy of the digitally LF based on magnetic resonance images to clarify the exact limits and edges of LF and its different thickness, depending on the area examined, while avoiding destructive methods, as well as the dissection processes. Anatomic cadaveric cross sections enabled us to visually check the definition of the edges along the entire LF and compare them using 3D image reconstruction methods. Reconstruction was performed in images obtained from 7 patients. Images from 1 patient were used as a basis for the 3D spinal anatomy tool. In parallel, axial cuts, 2 to 3 cm thick, were performed in lumbar spines of 4 frozen cadavers. This technique allowed us to identify the entire ligament and its exact limits, while avoiding alterations resulting from cutting processes or from preparation methods. The LF extended between the laminas of adjacent vertebrae at all vertebral levels of the patients examined, but midline gaps are regularly encountered. These anatomical variants were reproduced in a 3D portable document format. The major anatomical features of the LF were reproduced in the 3D model. Details of its structure and variations of thickness in successive sagittal and axial slides could be visualized. Gaps within LF previously studied in cadavers have been identified in our interactive 3D model, which may help to understand their nature, as well as possible implications for epidural techniques.

Using ventricular modeling to robustly probe significant deep gray matter pathologies: Application to cerebral palsy.

PubMed

Pagnozzi, Alex M; Shen, Kaikai; Doecke, James D; Boyd, Roslyn N; Bradley, Andrew P; Rose, Stephen; Dowson, Nicholas

2016-11-01

Understanding the relationships between the structure and function of the brain largely relies on the qualitative assessment of Magnetic Resonance Images (MRIs) by expert clinicians. Automated analysis systems can support these assessments by providing quantitative measures of brain injury. However, the assessment of deep gray matter structures, which are critical to motor and executive function, remains difficult as a result of large anatomical injuries commonly observed in children with Cerebral Palsy (CP). Hence, this article proposes a robust surrogate marker of the extent of deep gray matter injury based on impingement due to local ventricular enlargement on surrounding anatomy. Local enlargement was computed using a statistical shape model of the lateral ventricles constructed from 44 healthy subjects. Measures of injury on 95 age-matched CP patients were used to train a regression model to predict six clinical measures of function. The robustness of identifying ventricular enlargement was demonstrated by an area under the curve of 0.91 when tested against a dichotomised expert clinical assessment. The measures also showed strong and significant relationships for multiple clinical scores, including: motor function (r 2  = 0.62, P < 0.005), executive function (r 2  = 0.55, P < 0.005), and communication (r 2  = 0.50, P < 0.005), especially compared to using volumes obtained from standard anatomical segmentation approaches. The lack of reliance on accurate anatomical segmentations and its resulting robustness to large anatomical variations is a key feature of the proposed automated approach. This coupled with its strong correlation with clinically meaningful scores, signifies the potential utility to repeatedly assess MRIs for clinicians diagnosing children with CP. Hum Brain Mapp 37:3795-3809, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Surgical Techniques for the Reconstruction of Medial Collateral Ligament and Posteromedial Corner Injuries of the Knee: A Systematic Review.

PubMed

DeLong, Jeffrey M; Waterman, Brian R

2015-11-01

To systematically review reconstruction techniques of the medial collateral ligament (MCL) and associated medial structures of the knee (e.g., posterior oblique ligament). A systematic review of Medline/PubMed Database (1966 to November 2013), reference list scanning and citation searches of included articles, and manual searches of high-impact journals (2000 to July 2013) and conference proceedings (2009 to July 2013) were performed to identify publications describing MCL reconstruction techniques of the knee. Exclusion criteria included (1) MCL primary repair techniques or advancement procedures, (2) lack of clear description of MCL reconstruction technique, (3) animal models, (4) nonrelevant study design, (5) and foreign language articles without available translation. After review of 4,600 references, 25 publications with 359 of 388 patients (92.5%) were isolated for analysis, including 18 single-bundle MCL and 10 double-bundle reconstruction techniques. Only 2 techniques were classified as anatomic reconstructions, and clinical and objective outcomes (n = 28; 100% <3 mm side-to-side difference [SSD]) were superior to those with nonanatomic reconstruction (n = 182; 79.1% <3 mm SSD) and tendon transfer techniques (n = 114; 52.6% <3 mm SSD). This systematic review demonstrated that numerous medial reconstruction techniques have been used in the treatment of isolated and combined medial knee injuries in the existent literature. Many variations exist among reconstruction techniques and may differ by graft choices, method of fixation, number of bundles, tensioning protocol, and degree of anatomic restoration of medial and posteromedial corner knee restraints. Further studies are required to better ascertain the comparative clinical outcomes with anatomic, non-anatomic, and tendon transfer techniques for medial knee reconstruction. Level IV, systematic review of level IV studies and surgical techniques. Published by Elsevier Inc.

The feasibility of universal DLP-to-risk conversion coefficients for body CT protocols

NASA Astrophysics Data System (ADS)

Li, Xiang; Samei, Ehsan; Segars, W. Paul; Paulson, Erik K.; Frush, Donald P.

2011-03-01

The effective dose associated with computed tomography (CT) examinations is often estimated from dose-length product (DLP) using scanner-independent conversion coefficients. Such conversion coefficients are available for a small number of examinations, each covering an entire region of the body (e.g., head, neck, chest, abdomen and/or pelvis). Similar conversion coefficients, however, do not exist for examinations that cover a single organ or a sub-region of the body, as in the case of a multi-phase liver examination. In this study, we extended the DLP-to-effective dose conversion coefficient (k factor) to a wide range of body CT protocols and derived the corresponding DLP-to-cancer risk conversion coefficient (q factor). An extended cardiactorso (XCAT) computational model was used, which represented a reference adult male patient. A range of body CT protocols used in clinical practice were categorized based on anatomical regions examined into 10 protocol classes. A validated Monte Carlo program was used to estimate the organ dose associated with each protocol class. Assuming the reference model to be 20 years old, effective dose and risk index (an index of the total risk for cancer incidence) were then calculated and normalized by DLP to obtain the k and q factors. The k and q factors varied across protocol classes; the coefficients of variation were 28% and 9%, respectively. The small variation exhibited by the q factor suggested the feasibility of universal q factors for a wide range of body CT protocols.

Prevalence and variations of the median maxillary labial frenum in children, adolescents, and adults in a diverse population.

PubMed

Townsend, Janice A; Brannon, Robert B; Cheramie, Toby; Hagan, Joseph

2013-01-01

The median maxillary labial frenum (MMLF) is a normal anatomic structure with inherent morphologic variations. This study sought to evaluate the prevalence of those variations in a diverse ethnic population and to educate practitioners about the prevalence of MMLF variations to prevent unnecessary biopsies. This study included adult, adolescent, and child patients at the Louisiana State University Health Science Center School of Dentistry. Among the 284 subjects examined, frenum normale was the most common frenum classification, followed by frenum with nodule and frenum with appendix. Most nodules were found in the intermediate third of the MMLF, while appendices were mainly found in the labial third. The prevalence of an appendix was significantly higher (P < 0.001) in Caucasians compared to African-Americans. The prevalence of nodules was marginally higher (P = 0.096) in Caucasians than in African-Americans. No other statistically significant differences were found with regard to ethnicity. Additionally, nodules and appendices on the MMLF were identified in all age groups, and may become more common with increasing age. The authors determined that variations of the MMLF are inherent and do not represent a pathologic condition, nor do they require biopsy for diagnostic purposes.

Skin and mucosal ischemia as a complication after inferior alveolar nerve block.

PubMed

Aravena, Pedro Christian; Valeria, Camila; Nuñez, Nicolás; Perez-Rojas, Francisco; Coronado, Cesar

2016-01-01

The anesthetic block of the inferior alveolar nerve (IAN) is one of the most common techniques used in dental practice. The local complications are due to the failures on the anesthetic block or to anatomic variations in the tap site such as intravascular injection, skin ischemia and ocular problems. The aim of this article is to present a case and discuss the causes of itching and burning sensation, blanching, pain and face ischemia in the oral cavity during the IAN block.

Lymphoedema of the upper limb: a rare complication of thyroid surgery?

PubMed Central

Stephen, Christopher; Munnoch, David Alexander

2016-01-01

A 40-year-old woman underwent an elective thyroidectomy for a non-toxic, multinodular goitre. In the early postoperative period, the patient developed a significant unilateral swelling of the right upper limb, which was subsequently confirmed to be lymphoedema. This was eventually treated successfully using liposuction and compression garment therapies. We report the case due to its rarity and present a possible explanation for such an unexpected complication based on known anatomical variations of lymphatic drainage of the upper limb. PMID:27090542

[A mandibular second molar with three mesial roots: report of one case].

PubMed

Zhang, Ping

2010-02-01

A case of unusual root canal morphology was presented to demonstrate anatomic variations in mandibular second molars. This case report presented the endodontic therapy of a mandibular second molar with three canals in the mesial root. A mesial middle canal was found between the mesiobuccal and mesiolingual canals. This report indicated the importance of looking for additional canals and unusual canal morphology, because knowledge of their existence might occasionally enable clinicians to treat a case successfully that otherwise to fail.

A Hymen Epiphany.

PubMed

Jarral, Farrah

2015-01-01

The hymen is a structure of the female genitalia that is poorly understood even by many medical professionals. Despite the significant anatomical variation in the hymen and no guarantee that rupture or bleeding will occur at first coitus, it has come to hold major cultural significance around the world as a perceived biological indicator of virginity. The persistence of such myths around the hymen causes real harm, including the increase in so-called revirgination surgical procedures. Copyright 2015 The Journal of Clinical Ethics. All rights reserved.

Mandibular molar with five root canals.

PubMed

Barletta, Fernando Branco; Dotto, Sidney Ricardo; Reis, Magda de Sousa; Ferreira, Ronise; Travassos, Rosana Maria Coelho

2008-12-01

The purpose of this study was to demonstrate the importance of knowledge of the internal anatomy of root canals for the success of endodontic treatment. Lack of knowledge of anatomic variations and their characteristics in different teeth has been pointed out as one of the main causes of endodontic therapy failure. In this report, the authors describe the endodontic treatment of a mandibular first molar with five root canals, evaluate the rate of occurrence of this number of canals, and discuss the importance of their identification and treatment.

Low-dose 4D cone-beam CT via joint spatiotemporal regularization of tensor framelet and nonlocal total variation

NASA Astrophysics Data System (ADS)

Han, Hao; Gao, Hao; Xing, Lei

2017-08-01

Excessive radiation exposure is still a major concern in 4D cone-beam computed tomography (4D-CBCT) due to its prolonged scanning duration. Radiation dose can be effectively reduced by either under-sampling the x-ray projections or reducing the x-ray flux. However, 4D-CBCT reconstruction under such low-dose protocols is prone to image artifacts and noise. In this work, we propose a novel joint regularization-based iterative reconstruction method for low-dose 4D-CBCT. To tackle the under-sampling problem, we employ spatiotemporal tensor framelet (STF) regularization to take advantage of the spatiotemporal coherence of the patient anatomy in 4D images. To simultaneously suppress the image noise caused by photon starvation, we also incorporate spatiotemporal nonlocal total variation (SNTV) regularization to make use of the nonlocal self-recursiveness of anatomical structures in the spatial and temporal domains. Under the joint STF-SNTV regularization, the proposed iterative reconstruction approach is evaluated first using two digital phantoms and then using physical experiment data in the low-dose context of both under-sampled and noisy projections. Compared with existing approaches via either STF or SNTV regularization alone, the presented hybrid approach achieves improved image quality, and is particularly effective for the reconstruction of low-dose 4D-CBCT data that are not only sparse but noisy.

Serotonin and the Brain's Rich Club-Association Between Molecular Genetic Variation on the TPH2 Gene and the Structural Connectome.

PubMed

Markett, Sebastian; de Reus, Marcel A; Reuter, Martin; Montag, Christian; Weber, Bernd; Schoene-Bake, Jan-Christoph; van den Heuvel, Martijn P

2017-03-01

The rich club comprises a densely mutually connected set of hub regions in the brain, thought to serve as a processing and integration core. We assessed the impact of normal variation of the tryptophane hydroxylase 2 gene's promotor region (TPH2 rs4570625) on structural connectivity of the rich club pathways by means of a candidate gene association design. Tryptophane hydroxylase 2 (TPH2) is a rate-limiting enzyme in the biosynthesis of serotonin and is known to inhibit, in addition to its role as a trans-synaptic messenger, axonal and dendritic growth. The TPH2 T-variant has been associated with reduced mRNA expression and reduced serotonin levels, which may particularly influence the development of macroscale anatomical connectivity. Here, we show larger mean connectivity in the rich club in carriers of the T-variant, suggesting potential effects of upregulation of neural connectivity growth in this central core system. In addition, by edge-removal statistics, we show that the TPH2-associated higher levels of rich club connectivity are of importance for the functioning of the total structural network. The observed association is speculated to result from an effect of serotonin levels on brain development, potentially leading to stronger structural connectivity in heavily interconnected hubs. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Volumetric analysis of maxillary sinuses of Zulu and European crania by helical, multislice computed tomography.

PubMed

Fernandes, C L

2004-11-01

The volumes of the maxillary sinuses are of interest to surgeons operating endoscopically as variation in maxillary sinus volume may mean variation in anatomical landmarks. Other surgical disciplines, such as dentistry, maxillo-facial surgery and plastic surgery, may benefit from this information. To compare the maxillary sinus volumes of dried crania from cadavers of European and Zulu descent, with respect to ethnic group and gender. Helical, multislice computed tomography (CT) was performed using 1-mm coronal slices. The area for each slice was obtained by tracing the outline of each slice. The CT machine calculated a volume by totalling the slices for each sinus. Ethnic and gender variations were found in the different groups. It was found that European crania had significantly larger antral volumes than Zulu crania and men had larger volumes than women. Race and gender interaction was also assessed, as was maxillary sinus side. A variation in maxillary sinus volume between different ethnic groups and genders exists, and surgeons operating in this region should be aware of this.

Multiple variations of the coeliac axis, hepatic and renal vasculature as incidental findings illustrated by MDCTA.

PubMed

Rafailidis, Vasileios; Papadopoulos, Georgios; Kouskouras, Konstantinos; Chryssogonidis, Ioannis; Velnidou, Anastasia; Kalogera-Fountzila, Anna

2016-08-01

Vascular anatomical variations are not uncommon and may affect any organ's arterial or venous vasculature. The coexistence of variations in different organic systems is less commonly found, but of great clinical significance in a series of clinical conditions like organ transplantation and surgical preoperative planning. Multidetector computed tomography angiography (MDCTA) has emerged as a valuable alternative to the conventional angiography for accurate evaluation of vascular anatomy and pathology. Radiologists should be familiar with each organ's vascular variations and always report them to the clinician, even if they represent an incidental finding. This case report presents a 52-year-old female patient undergoing abdominal MDCTA for characterization of a renal lesion. This examination revealed the presence of three hilar arteries on the left kidney, a main renal vein in combination with an additional renal vein in both sides along with a replaced right hepatic artery originating from the superior mesenteric artery. Moreover, both inferior phrenic arteries were found originating from the coeliac axis. 3D volume rendering technique images were used in the evaluation of vascular anatomy as illustrated in this case report.

Maxillary molars with morphologic variations of the palatal root canals: a report of four cases.

PubMed

Holderrieth, Silke; Gernhardt, Christian Ralf

2009-07-01

The purpose of this article was to show the importance of the knowledge of the anatomy of root canals. Unusual root and root canal morphologies associated with both buccal roots of upper molars have been recorded in several studies in the literature. However, scientific information focusing on variations of the palatal root is rare. In this report, four cases are presented involving the root canal treatment of maxillary first and second molars with unusual morphologic configurations of the palatal root canals. During root canal treatment, type IV and V configurations as defined by Vertucci of the palatal canals of two first and two second maxillary molars were identified. After mechanical instrumentation, the canals were obturated. Radiologic and clinical re-evaluation showed no signs of inflammation. This report describes and discusses the possibility of different root and canal variations of the maxillary molars from a clinical point of view. Anatomic variations can occur in any tooth, and palatal roots of maxillary first and second molars are no exception. Therefore, careful examination of radiographs and internal anatomy of teeth is essential.

Effectiveness of Synthetic Polyurethane Foam as a Nasal Packing Material in Endoscopic Endonasal Dacryocystorhinostomy.

PubMed

Lee, Joonsik; Lee, Hwa; Lee, Hyun Kyu; Chang, Minwook; Park, Minsoo; Baek, Sehyun

2015-10-01

To compare the effects of 2 nasal packing materials, synthetic polyurethane foam (absorbable) and expandable polyvinyl acetate (nonabsorbable), on the surgical success rate and postoperative complications after endoscopic endonasal dacryocystorhinostomy (EDCR). A retrospective medical review of 459 patients (580 eyes) who underwent EDCR for primary acquired nasolacrimal duct obstruction at Korea University Guro Hospitals from January 2009 to February 2014. Surgical success rate (anatomical, functional), postoperative complications (granuloma, synechia, bleeding, and infection) were compared between the 2 groups, absorbable (318 eyes) and nonabsorbable (262 eyes). The absorbable group showed better results in surgical success rate regarding anatomical (90.5% versus 76.3%, P = 0.00) and functional (89.3% versus 75.9%, P = 0.00). Granulomas developed less frequently in the absorbable group (24.5% versus 38.9%, P = 0.00). Also, bleeding and crust were less frequent in the absorbable group (P = 0.00). Infections were less frequent in the nonabsorbable group (1.52%) compared with the absorbable group (7.86%, P = 0.00). The rate of revision surgery was lower in the absorbable group (7.86% versus 20.9%, P = 0.00). As for the influence of secondary outcomes to the surgical success by multiple logistic regression, granulomas had the largest effect on surgical success either anatomical or functional (odds ratio = 82.393 to anatomical and 44.058 to functional). Synechia had the second largest effect on surgical success (odds ratio = 11.897 to anatomical and 9.605 to functional). The authors suggest that using a synthetic polyurethane foam as a nasal packing material is not only a surgical option, but also a crucial and essential procedure in EDCR.

A Model of Regularization Parameter Determination in Low-Dose X-Ray CT Reconstruction Based on Dictionary Learning

PubMed Central

Zhang, Cheng; Zhang, Tao; Li, Ming; Lu, Yanfei; You, Jiali; Guan, Yihui

2015-01-01

In recent years, X-ray computed tomography (CT) is becoming widely used to reveal patient's anatomical information. However, the side effect of radiation, relating to genetic or cancerous diseases, has caused great public concern. The problem is how to minimize radiation dose significantly while maintaining image quality. As a practical application of compressed sensing theory, one category of methods takes total variation (TV) minimization as the sparse constraint, which makes it possible and effective to get a reconstruction image of high quality in the undersampling situation. On the other hand, a preliminary attempt of low-dose CT reconstruction based on dictionary learning seems to be another effective choice. But some critical parameters, such as the regularization parameter, cannot be determined by detecting datasets. In this paper, we propose a reweighted objective function that contributes to a numerical calculation model of the regularization parameter. A number of experiments demonstrate that this strategy performs well with better reconstruction images and saving of a large amount of time. PMID:26550024

Role of the serotonin 5-HT(2A) receptor in learning.

PubMed

Harvey, John A

2003-01-01

This study reviews the role of the serotonin 5-HT2A receptor in learning as measured by the acquisition of the rabbit's classically conditioning nictitating membrane response, a component of the eyeblink response. Agonists at the 5-HT2A receptor including LSD (d-lysergic acid diethylamide) enhanced associative learning at doses that produce cognitive effects in humans. Some antagonists such as BOL (d-bromolysergic acid diethylamide), LY53,857, and ketanserin acted as neutral antagonists in that they had no effect on learning, whereas others (MDL11,939, ritanserin, and mianserin) acted as inverse agonists in that they retarded learning through an action at the 5-HT2A receptor. These results were placed in the context of what is known concerning the anatomical distribution and electrophysiological effects of 5-HT2A receptor activation in frontal cortex and hippocampus, as well as the role of cortical 5-HT2A receptors in schizophrenia. It was concluded that the 5-HT2A receptor demonstrates constitutive activity, and that variations in this activity can produce profound alterations in cognitive states.

A systematic review of studies on anatomical position of electrode contacts used for chronic subthalamic stimulation in Parkinson's disease.

PubMed

Caire, François; Ranoux, Danièle; Guehl, Dominique; Burbaud, Pierre; Cuny, Emmanuel

2013-09-01

The dorso-lateral part of the subthalamic nucleus (STN) is considered as the usual target of deep brain stimulation for Parkinson's disease. Nevertheless, the exact anatomical location of the electrode contacts used for chronic stimulation is still a matter of debate. The aim of this study was to perform a systematic review of the existing literature on this issue. We searched for studies on the anatomical location of active contacts published until December 2012. We identified 13 studies, published between 2002 and 2010, including 260 patients and 466 electrodes. One hundred and sixty-four active contacts (35 %) were identified within the STN, 117 (25 %) at the interface between STN and the surrounding structures, 184 (40 %) above the STN and one within the substantia nigra. We observed great discrepancies between the different series. The contra-lateral improvement was between 37 and 78.5 % for contacts located within the STN, between 48.6 and 73 % outside the STN, between 65.3 and 66 % at the interface. The authors report no clear correlation between anatomical location and stimulation parameters. Post-operative analysis of the anatomical location of active contacts is difficult, and all the methods used are debatable. The relationship between the anatomical location of active contacts and the clinical effectiveness of stimulation is unclear. It would be necessary to take into account the volume of the electrode contacts and the diffusion of the stimulation. We can nevertheless assume that the interface between dorso-lateral STN, zona incerta and Forel's fields could be directly involved in the effects of stimulation.

Improving thoracic four-dimensional cone-beam CT reconstruction with anatomical-adaptive image regularization (AAIR)

PubMed Central

Shieh, Chun-Chien; Kipritidis, John; O’Brien, Ricky T; Cooper, Benjamin J; Kuncic, Zdenka; Keall, Paul J

2015-01-01

Total-variation (TV) minimization reconstructions can significantly reduce noise and streaks in thoracic four-dimensional cone-beam computed tomography (4D CBCT) images compared to the Feldkamp-Davis-Kress (FDK) algorithm currently used in practice. TV minimization reconstructions are, however, prone to over-smoothing anatomical details and are also computationally inefficient. The aim of this study is to demonstrate a proof of concept that these disadvantages can be overcome by incorporating the general knowledge of the thoracic anatomy via anatomy segmentation into the reconstruction. The proposed method, referred as the anatomical-adaptive image regularization (AAIR) method, utilizes the adaptive-steepest-descent projection-onto-convex-sets (ASD-POCS) framework, but introduces an additional anatomy segmentation step in every iteration. The anatomy segmentation information is implemented in the reconstruction using a heuristic approach to adaptively suppress over-smoothing at anatomical structures of interest. The performance of AAIR depends on parameters describing the weighting of the anatomy segmentation prior and segmentation threshold values. A sensitivity study revealed that the reconstruction outcome is not sensitive to these parameters as long as they are chosen within a suitable range. AAIR was validated using a digital phantom and a patient scan, and was compared to FDK, ASD-POCS, and the prior image constrained compressed sensing (PICCS) method. For the phantom case, AAIR reconstruction was quantitatively shown to be the most accurate as indicated by the mean absolute difference and the structural similarity index. For the patient case, AAIR resulted in the highest signal-to-noise ratio (i.e. the lowest level of noise and streaking) and the highest contrast-to-noise ratios for the tumor and the bony anatomy (i.e. the best visibility of anatomical details). Overall, AAIR was much less prone to over-smoothing anatomical details compared to ASD-POCS, and did not suffer from residual noise/streaking and motion blur migrated from the prior image as in PICCS. AAIR was also found to be more computationally efficient than both ASD-POCS and PICCS, with a reduction in computation time of over 50% compared to ASD-POCS. The use of anatomy segmentation was, for the first time, demonstrated to significantly improve image quality and computational efficiency for thoracic 4D CBCT reconstruction. Further developments are required to facilitate AAIR for practical use. PMID:25565244

Three-dimensional automatic computer-aided evaluation of pleural effusions on chest CT images

NASA Astrophysics Data System (ADS)

Bi, Mark; Summers, Ronald M.; Yao, Jianhua

2011-03-01

The ability to estimate the volume of pleural effusions is desirable as it can provide information about the severity of the condition and the need for thoracentesis. We present here an improved version of an automated program to measure the volume of pleural effusions using regular chest CT images. First, the lungs are segmented using region growing, mathematical morphology, and anatomical knowledge. The visceral and parietal layers of the pleura are then extracted based on anatomical landmarks, curve fitting and active contour models. The liver and compressed tissues are segmented out using thresholding. The pleural space is then fitted to a Bezier surface which is subsequently projected onto the individual two-dimensional slices. Finally, the volume of the pleural effusion is quantified. Our method was tested on 15 chest CT studies and validated against three separate manual tracings. The Dice coefficients were 0.74+/-0.07, 0.74+/-0.08, and 0.75+/-0.07 respectively, comparable to the variation between two different manual tracings.

Simulation-based planning of surgical interventions in pediatric cardiology

NASA Astrophysics Data System (ADS)

Marsden, Alison

2012-11-01

Hemodynamics plays an essential role in the progression and treatment of cardiovascular disease. This is particularly true in pediatric cardiology, due to the wide variation in anatomy observed in congenital heart disease patients. While medical imaging provides increasingly detailed anatomical information, clinicians currently have limited knowledge of important fluid mechanical parameters. Treatment decisions are therefore often made using anatomical information alone, despite the known links between fluid mechanics and disease progression. Patient-specific simulations now offer the means to provide this missing information, and, more importantly, to perform in-silico testing of new surgical designs at no risk to the patient. In this talk, we will outline the current state of the art in methods for cardiovascular blood flow simulation and virtual surgery. We will then present new methodology for coupling optimization with simulation and uncertainty quantification to customize treatments for individual patients. Finally, we will present examples in pediatric cardiology that illustrate the potential impact of these tools in the clinical setting.

Colour flow and motion imaging.

PubMed

Evans, D H

2010-01-01

Colour flow imaging (CFI) is an ultrasound imaging technique whereby colour-coded maps of tissue velocity are superimposed on grey-scale pulse-echo images of tissue anatomy. The most widespread use of the method is to image the movement of blood through arteries and veins, but it may also be used to image the motion of solid tissue. The production of velocity information is technically more demanding than the production of the anatomical information, partly because the target of interest is often blood, which backscatters significantly less power than solid tissues, and partly because several transmit-receive cycles are necessary for each velocity estimate. This review first describes the various components of basic CFI systems necessary to generate the velocity information and to combine it with anatomical information. It then describes a number of variations on the basic autocorrelation technique, including cross-correlation-based techniques, power Doppler, Doppler tissue imaging, and three-dimensional (3D) Doppler imaging. Finally, a number of limitations of current techniques and some potential solutions are reviewed.

Automated atlas-based clustering of white matter fiber tracts from DTMRI.

PubMed

Maddah, Mahnaz; Mewes, Andrea U J; Haker, Steven; Grimson, W Eric L; Warfield, Simon K

2005-01-01

A new framework is presented for clustering fiber tracts into anatomically known bundles. This work is motivated by medical applications in which variation analysis of known bundles of fiber tracts in the human brain is desired. To include the anatomical knowledge in the clustering, we invoke an atlas of fiber tracts, labeled by the number of bundles of interest. In this work, we construct such an atlas and use it to cluster all fiber tracts in the white matter. To build the atlas, we start with a set of labeled ROIs specified by an expert and extract the fiber tracts initiating from each ROI. Affine registration is used to project the extracted fiber tracts of each subject to the atlas, whereas their B-spline representation is used to efficiently compare them to the fiber tracts in the atlas and assign cluster labels. Expert visual inspection of the result confirms that the proposed method is very promising and efficient in clustering of the known bundles of fiber tracts.

Influence of Environment on Glandular Trichomes and Composition of Essential Oil of Perovskia abrotanoides Karel.

PubMed

Oreizi, Elaheh; Rahiminejad, Mohammad Reza; Asghari, Gholamreza

2014-11-01

Perovskia abrotanoides Karel. is a medicinal plant used in Iranian folk medicine as a pain killer. Forty-one components have been identified in P. abrotanoides samples collected from Baluchistan Province, and 29 components have been recognized in samples collected from Khorasan Province. The leaves of P. abrotanoides have glandular trichomes (capitates and peltate) on both sides of the lamina. This study aimed to evaluate the variation of oil constituents of the plant and illustrate the glandular trichomes types and then show the influence of environment on oil constituents and glandular trichomes. The essential oil of the plant was obtained using hydrodistillation and the analysis of oils carried out using GC-MS. The anatomical analysis of leaves was done by fixing, coloring, and photoing the sections. Glandular trichomes composed of capitates and peltate trichomes. The essential oil composition differs. Viridiflora and neryl acetate were not identified in yellow glandular trichomes. It seems that there is no relation between anatomical characteristics of the plant leaves and its essential oil composition.

Whole-body and local RF absorption in human models as a function of anatomy and position within 1.5T MR body coil.

PubMed

Murbach, Manuel; Neufeld, Esra; Kainz, Wolfgang; Pruessmann, Klaas P; Kuster, Niels

2014-02-01

Radiofrequency energy deposition in magnetic resonance imaging must be limited to prevent excessive heating of the patient. Correlations of radiofrequency absorption with large-scale anatomical features (e.g., height) are investigated in this article. The specific absorption rate (SAR), as the pivotal parameter for quantifying absorbed radiofrequency, increases with the radial dimension of the patient and therefore with the large-scale anatomical properties. The absorbed energy in six human models has been modeled in different Z-positions (head to knees) within a 1.5T bodycoil. For a fixed B1+ incident field, the whole-body SAR can be up to 2.5 times higher (local SAR up to seven times) in obese adult models compared to children. If the exposure is normalized to 4 W/kg whole-body SAR, the local SAR can well-exceed the limits for local transmit coils and shows intersubject variations of up to a factor of three. The correlations between anatomy and induced local SAR are weak for normalized exposure, but strong for a fixed B1+ field, suggesting that anatomical properties could be used for fast SAR predictions. This study demonstrates that a representative virtual human population is indispensable for the investigation of local SAR levels. Copyright © 2013 Wiley Periodicals, Inc.

Genomic evidence for an African expansion of anatomically modern humans by a Southern route.

PubMed

Ghirotto, Silvia; Penso-Dolfin, Luca; Barbujani, Guido

2011-08-01

There is general agreement among scientists about a recent (less than 200,000 yrs ago) African origin of anatomically modern humans, whereas there is still uncertainty about whether, and to what extent, they admixed with archaic populations, which thus may have contributed to the modern populations' gene pools. Data on cranial morphology have been interpreted as suggesting that, before the main expansion from Africa through the Near East, anatomically modern humans may also have taken a Southern route from the Horn of Africa through the Arabian peninsula to India, Melanesia and Australia, about 100,000 yrs ago. This view was recently supported by archaeological findings demonstrating human presence in Eastern Arabia >90,000 yrs ago. In this study we analyzed genetic variation at 111,197 nuclear SNPs in nine populations (Kurumba, Chenchu, Kamsali, Madiga, Mala, Irula, Dalit, Chinese, Japanese), chosen because their genealogical relationships are expected to differ under the alternative models of expansion (single vs. multiple dispersals). We calculated correlations between genomic distances, and geographic distances estimated under the alternative assumptions of a single dispersal, or multiple dispersals, and found a significantly stronger association for the multiple dispersal model. If confirmed, this result would cast doubts on the possibility that some non-African populations (i.e., those whose ancestors expanded through the Southern route) may have had any contacts with Neandertals.

Anatomical Footprint of the Tibialis Anterior Tendon: Surgical Implications for Foot and Ankle Reconstructions.

PubMed

Willegger, Madeleine; Seyidova, Nargiz; Schuh, Reinhard; Windhager, Reinhard; Hirtler, Lena

2017-01-01

This study aimed to analyze precisely the dimensions, shapes, and variations of the insertional footprints of the tibialis anterior tendon (TAT) at the medial cuneiform (MC) and first metatarsal (MT1) base. Forty-one formalin-fixed human cadaveric specimens were dissected. After preparation of the TAT footprint, standardized photographs were made and the following parameters were evaluated: the footprint length, width, area of insertion, dorsoplantar location, shape, and additional tendon slips. Twenty feet (48.8%) showed an equal insertion at the MC and MT1, another 20 feet (48.8%) had a wide insertion at the MC and a narrow insertion at the MT1, and 1 foot (2.4%) demonstrated a narrow insertion at the MC and a wide insertion at the MT1. Additional tendon slips inserting at the metatarsal shaft were found in two feet (4.8%). Regarding the dorsoplantar orientation, the footprints were located medial in 29 feet (70.7%) and medioplantar in 12 feet (29.3%). The most common shape at the MT1 base was the crescent type (75.6%) and the oval type at the MC (58.5%). The present study provided more detailed data on the dimensions and morphologic types of the tibialis anterior tendon footprint. The established anatomical data may allow for a safer surgical preparation and a more anatomical reconstruction.

Use of optical coherence tomography in delineating airways microstructure: comparison of OCT images to histopathological sections

NASA Astrophysics Data System (ADS)

Yang, Ying; Whiteman, Suzanne; Gey van Pittius, Daniel; He, Yonghong; Wang, Ruikang K.; Spiteri, Monica A.

2004-04-01

An ideal diagnostic system for the human airways should be able to detect and define early development of premalignant pathological lesions, to facilitate optimal curative treatment and prevent irreversible and/or invasive lung disease. There is great need for exploration of safe, repeatable imaging techniques which can run at real-time and with high spatial resolution. In this study, optical coherence tomography (OCT) was utilized to acquire cross-sectional images of upper and lower airways using fresh pig lung resections as a model system. Obtained OCT images were compared with parallel tissue characterization by conventional histological analysis. Our objective was to determine whether OCT differentiates the composite structural layers and inherent anatomical variations along different airway locations. The data show that OCT can clearly display the multilayered structure of the airways. The subtle architectural differences in three separate anatomical locations including trachea, main bronchus and tertiary bronchus were clearly delineated. Images of the appropriate anatomical profiles, with depth of up to 2 mm and 10 µm spatial resolution were obtained by our current OCT system, which was sufficient for recognition of the epithelium, subepithelial tissues and cartilage. In addition, the relative thickness of individual structural components was accurately reflected and comparable to histological sections. These data support OCT as a highly feasible, optical biopsy tool, which merits further exploration for early diagnosis of human airway epithelial pathology.

The Anatomical Distance of Functional Connections Predicts Brain Network Topology in Health and Schizophrenia

PubMed Central

Vértes, Petra E.; Stidd, Reva; Lalonde, François; Clasen, Liv; Rapoport, Judith; Giedd, Jay; Bullmore, Edward T.; Gogtay, Nitin

2013-01-01

The human brain is a topologically complex network embedded in anatomical space. Here, we systematically explored relationships between functional connectivity, complex network topology, and anatomical (Euclidean) distance between connected brain regions, in the resting-state functional magnetic resonance imaging brain networks of 20 healthy volunteers and 19 patients with childhood-onset schizophrenia (COS). Normal between-subject differences in average distance of connected edges in brain graphs were strongly associated with variation in topological properties of functional networks. In addition, a club or subset of connector hubs was identified, in lateral temporal, parietal, dorsal prefrontal, and medial prefrontal/cingulate cortical regions. In COS, there was reduced strength of functional connectivity over short distances especially, and therefore, global mean connection distance of thresholded graphs was significantly greater than normal. As predicted from relationships between spatial and topological properties of normal networks, this disorder-related proportional increase in connection distance was associated with reduced clustering and modularity and increased global efficiency of COS networks. Between-group differences in connection distance were localized specifically to connector hubs of multimodal association cortex. In relation to the neurodevelopmental pathogenesis of schizophrenia, we argue that the data are consistent with the interpretation that spatial and topological disturbances of functional network organization could arise from excessive “pruning” of short-distance functional connections in schizophrenia. PMID:22275481

The "safe zone" in medial percutaneous calcaneal pin placement.

PubMed

Gamie, Zakareya; Donnelly, Leo; Tsiridis, Eleftherios

2009-05-01

Percutaneous pin insertion into the medial calcaneus places a number of structures at risk. Evidence suggests that the greatest risk is to the medial calcaneal nerve (MCN). The medial calcaneal region of 24 cadavers was dissected to determine the major structures at risk. By using four palpable anatomical landmarks, the inferior tip of the medial malleolus (point A), the posterior superior portion of the calcaneal tuberosity (point B), the navicular tuberosity (point C), and the medial process of the calcaneal tuberosity (point D), we attempted to define the safe zone taking into account all possible variables in our dissections including ankle position, side, gender, and possible anatomical variations of the MCN. The commonest arrangement of the MCN was two MCNs that arose independently, one arising before the bifurcation of the tibial nerve and the other arising from the medial plantar nerve. A zone could be defined posterior to 75% of the distance along the lines AB, CD, AD, and CB which would avoid most structures. The posterior branches of the MCN, however, would still be at risk and placing the pin too far posteriorly risks an avulsion fracture. This is the first study to employ four palpable anatomical landmarks to identify a zone to minimize damage to neurovascular structures. It may not be possible, however, to avoid injury of the MCN and consequent sensory loss to the sole of the foot.

Intra-abdominal temperature distribution during consolidation hyperthermic intraperitoneal chemotherapy with carboplatin in the treatment of advanced stage ovarian carcinoma.

PubMed

Rettenmaier, Mark A; Mendivil, Alberto A; Gray, Crystal M; Chapman, Amber P; Stone, Michelle K; Tinnerman, Erin J; Goldstein, Bram H

2015-06-01

Hyperthermic intraperitoneal chemotherapy (HIPEC) involves the continuous heating and circulation of chemotherapy throughout the abdominal cavity in an attempt to enhance cytotoxicity. Despite the potential of this chemotherapy procedure, there are scant anatomical temperature distribution studies reporting on this therapeutic process. We prospectively evaluated the temperature of select anatomical (e.g. upper abdominal, mid-abdominal and supra-pubic) sites in 11 advanced stage ovarian cancer patients who were treated with consolidation HIPEC carboplatin (AUC 10). The temperature of the aforementioned anatomical regions and the inflow/outflow tubing was measured at baseline and at 15-min intervals until the procedure's completion. The lowest observed mean composite temperature was 41.1 °C at the supra-pubic site whereas the highest temperature was 42.6 °C, in association with the inflow/outflow tubing. During the various time intervals we also ascertained that the lowest composite temperature was 40.9 °C at baseline (i.e. time 0), whereas the highest value (41.8 °C) occurred at multiple time periods (e.g., 15, 45 and 60 min). The HIPEC temperature variation amongst the various abdominal sites and time intervals was minimal. We also discerned that uniform temperature distribution throughout the abdominal cavity was facilitated when the abdomen was both maximally distended with fluid and a high flow rate was maintained.

General organization of the human intra-masseteric aponeuroses: changes with ageing.

PubMed

Brunel, G; El-Haddioui, A; Bravetti, P; Zouaoui, A; Gaudy, J-F

2003-01-01

A magnetic resonance imaging (MRI) study of the layout of the aponeurotic layers of the masseter muscle was done on a series of 18 patients, aged from 6 to 79 years. The study was undertaken in parallel with a study on 169 cadavers to correlate the anatomical dissection and MRI findings. The aims were as follows. On the cadavers, the results of dissection were compared with the results of MRI: the layer-by-layer dissections and the anatomical dissections of the different spatial planes have shown that the masseter muscle displays a penniform structure typically characterized by the presence of alternating muscular/aponeurotic layers. The anatomical sections and the MRI section in the same plane allowed the appearance of the intra-muscular aponeurotic layers on MRI to be defined. The patients were then divided into four age cohorts, and the arrangement and variations of the human masseter muscle defined as a function of age. This double study has brought new elements to the understanding of the timing of the development of the intra-muscular aponeurotic structures and the modifications which they undergo with ageing. It appears that the aponeurotic structures only become individually identifiable towards the age of 17 years and that ageing is accompanied by a reduction in the transverse muscular mass accompanied by a verticalization of the aponeurotic layers.

Anatomical modeling of the bronchial tree

NASA Astrophysics Data System (ADS)

Hentschel, Gerrit; Klinder, Tobias; Blaffert, Thomas; Bülow, Thomas; Wiemker, Rafael; Lorenz, Cristian

2010-02-01

The bronchial tree is of direct clinical importance in the context of respective diseases, such as chronic obstructive pulmonary disease (COPD). It furthermore constitutes a reference structure for object localization in the lungs and it finally provides access to lung tissue in, e.g., bronchoscope based procedures for diagnosis and therapy. This paper presents a comprehensive anatomical model for the bronchial tree, including statistics of position, relative and absolute orientation, length, and radius of 34 bronchial segments, going beyond previously published results. The model has been built from 16 manually annotated CT scans, covering several branching variants. The model is represented as a centerline/tree structure but can also be converted in a surface representation. Possible model applications are either to anatomically label extracted bronchial trees or to improve the tree extraction itself by identifying missing segments or sub-trees, e.g., if located beyond a bronchial stenosis. Bronchial tree labeling is achieved using a naïve Bayesian classifier based on the segment properties contained in the model in combination with tree matching. The tree matching step makes use of branching variations covered by the model. An evaluation of the model has been performed in a leaveone- out manner. In total, 87% of the branches resulting from preceding airway tree segmentation could be correctly labeled. The individualized model enables the detection of missing branches, allowing a targeted search, e.g., a local rerun of the tree-segmentation segmentation.

Stomatal conductance, mesophyll conductance, and transpiration efficiency in relation to leaf anatomy in rice and wheat genotypes under drought.

PubMed

Ouyang, Wenjing; Struik, Paul C; Yin, Xinyou; Yang, Jianchang

2017-11-02

Increasing leaf transpiration efficiency (TE) may provide leads for growing rice like dryland cereals such as wheat (Triticum aestivum). To explore avenues for improving TE in rice, variations in stomatal conductance (gs) and mesophyll conductance (gm) and their anatomical determinants were evaluated in two cultivars from each of lowland, aerobic, and upland groups of Oryza sativa, one cultivar of O. glaberrima, and two cultivars of T. aestivum, under three water regimes. The TE of upland rice, O. glaberrima, and wheat was more responsive to the gm/gs ratio than that of lowland and aerobic rice. Overall, the explanatory power of the particular anatomical trait varied among species. Low stomatal density mostly explained the low gs in drought-tolerant rice, whereas rice genotypes with smaller stomata generally responded more strongly to drought. Compared with rice, wheat had a higher gm, which was associated with thicker mesophyll tissue, mesophyll and chloroplasts more exposed to intercellular spaces, and thinner cell walls. Upland rice, O. glaberrima, and wheat cultivars minimized the decrease in gm under drought by maintaining high ratios of chloroplasts to exposed mesophyll cell walls. Rice TE could be improved by increasing the gm/gs ratio via modifying anatomical traits. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

Confirmation of an anatomic variation of the recurrent laryngeal nerve at site of entry into the larynx in Chinese population.

PubMed

Shao, Tanglei; Qiu, Weihua; Yang, Weiping

2016-01-01

This study was aimed at analyzing the frequency of the newly reported variation and the frequency of postoperative palsy associated with three different kinds of known variations. We conducted a retrospective study on the data of 2068 consecutive Chinese patients who underwent thyroidectomy. The study included 1362 left and 1507 right (2869 in total) RLNs. Among all the RLNs, 548 were found to have variations at the laryngeal entry of the RLN. The most frequent variation was extralaryngeal branching (n=322), followed by the fan-shaped branching (n=201). Our newly identified variation was also noted in 25 of our patients. In these cases, the RLN entered the larynx from sites that were distant from the posterior cricothyroid joint. The distance from the entry of the RLN to the back of cricothyroid joints was over 5mm. Compared to the rates reported from other countries, the rate of the first type of variation is lower, while that of the second type is higher. The frequency of the new variation has not been reported in other populations, but it is consistent with our previous finding. The incidence of postoperative palsy was greater for RLNs with the first and third types of variations than in the normal RLNs. We confirmed that the incidence of patients with the new type of variation of the RLN at the entry of the larynx was about 1% in Chinese. Awareness among surgeons regarding this variation is important to avoid postoperative palsy. Copyright © 2016 Elsevier Inc. All rights reserved.

On the Influence of Confounding Factors in Multisite Brain Morphometry Studies of Developmental Pathologies: Application to Autism Spectrum Disorder.

PubMed

Auzias, G; Takerkart, S; Deruelle, C

2016-05-01

Pooling data acquired on different MR scanners is a commonly used practice to increase the statistical power of studies based on MRI-derived measurements. Such studies are very appealing since they should make it possible to detect more subtle effects related to pathologies. However, the influence of confounds introduced by scanner-related variations remains unclear. When studying brain morphometry descriptors, it is crucial to investigate whether scanner-induced errors can exceed the effect of the disease itself. More specifically, in the context of developmental pathologies such as autism spectrum disorders (ASD), it is essential to evaluate the influence of the scanner on age-related effects. In this paper, we studied a dataset composed of 159 anatomical MR images pooled from three different scanners, including 75 ASD patients and 84 healthy controls. We quantitatively assessed the effects of the age, pathology, and scanner factors on cortical thickness measurements. Our results indicate that scan pooling from different sites would be less fruitful in some cortical regions than in others. Although the effect of age is consistent across scanners, the interaction between the age and scanner factors is important and significant in some specific cortical areas.

Numerical Models of Human Circulatory System under Altered Gravity: Brain Circulation

NASA Technical Reports Server (NTRS)

Kim, Chang Sung; Kiris, Cetin; Kwak, Dochan; David, Tim

2003-01-01

A computational fluid dynamics (CFD) approach is presented to model the blood flow through the human circulatory system under altered gravity conditions. Models required for CFD simulation relevant to major hemodynamic issues are introduced such as non-Newtonian flow models governed by red blood cells, a model for arterial wall motion due to fluid-wall interactions, a vascular bed model for outflow boundary conditions, and a model for auto-regulation mechanism. The three-dimensional unsteady incompressible Navier-Stokes equations coupled with these models are solved iteratively using the pseudocompressibility method and dual time stepping. Moving wall boundary conditions from the first-order fluid-wall interaction model are used to study the influence of arterial wall distensibility on flow patterns and wall shear stresses during the heart pulse. A vascular bed modeling utilizing the analogy with electric circuits is coupled with an auto-regulation algorithm for multiple outflow boundaries. For the treatment of complex geometry, a chimera overset grid technique is adopted to obtain connectivity between arterial branches. For code validation, computed results are compared with experimental data for steady and unsteady non-Newtonian flows. Good agreement is obtained for both cases. In sin-type Gravity Benchmark Problems, gravity source terms are added to the Navier-Stokes equations to study the effect of gravitational variation on the human circulatory system. This computational approach is then applied to localized blood flows through a realistic carotid bifurcation and two Circle of Willis models, one using an idealized geometry and the other model using an anatomical data set. A three- dimensional anatomical Circle of Willis configuration is reconstructed from human-specific magnetic resonance images using an image segmentation method. The blood flow through these Circle of Willis models is simulated to provide means for studying gravitational effects on the brain circulation under auto-regulation.

The effect of anatomical modeling on space radiation dose estimates: a comparison of doses for NASA phantoms and the 5th, 50th, and 95th percentile male and female astronauts.

PubMed

Bahadori, Amir A; Van Baalen, Mary; Shavers, Mark R; Dodge, Charles; Semones, Edward J; Bolch, Wesley E

2011-03-21

The National Aeronautics and Space Administration (NASA) performs organ dosimetry and risk assessment for astronauts using model-normalized measurements of the radiation fields encountered in space. To determine the radiation fields in an organ or tissue of interest, particle transport calculations are performed using self-shielding distributions generated with the computer program CAMERA to represent the human body. CAMERA mathematically traces linear rays (or path lengths) through the computerized anatomical man (CAM) phantom, a computational stylized model developed in the early 1970s with organ and body profiles modeled using solid shapes and scaled to represent the body morphometry of the 1950 50th percentile (PCTL) Air Force male. With the increasing use of voxel phantoms in medical and health physics, a conversion from a mathematical-based to a voxel-based ray-tracing algorithm is warranted. In this study, the voxel-based ray tracer (VoBRaT) is introduced to ray trace voxel phantoms using a modified version of the algorithm first proposed by Siddon (1985 Med. Phys. 12 252-5). After validation, VoBRAT is used to evaluate variations in body self-shielding distributions for NASA phantoms and six University of Florida (UF) hybrid phantoms, scaled to represent the 5th, 50th, and 95th PCTL male and female astronaut body morphometries, which have changed considerably since the inception of CAM. These body self-shielding distributions are used to generate organ dose equivalents and effective doses for five commonly evaluated space radiation environments. It is found that dosimetric differences among the phantoms are greatest for soft radiation spectra and light vehicular shielding.

Correction Capability in the 3 Anatomic Planes of Different Pedicle Screw Designs in Scoliosis Instrumentation.

PubMed

Wang, Xiaoyu; Aubin, Carl-Eric; Coleman, John; Rawlinson, Jeremy

2017-05-01

Computer simulations to compare the correction capabilities of different pedicle screws in adolescent idiopathic scoliosis (AIS) instrumentations. To compare the correction and resulting bone-screw forces associated with different pedicle screws in scoliosis instrumentations. Pedicle screw fixation is widely used in surgical instrumentation for spinal deformity treatment. Screw design, correction philosophies, and surgical techniques are constantly evolving to achieve better control of the vertebrae and correction of the spinal deformity. Yet, there remains a lack of biomechanical studies that quantify the effects and advantages of different screw designs in terms of correction kinematics. The correction capabilities of fixed-angle, multiaxial, uniaxial, and saddle axial screws were kinematically analyzed, simulated, and compared. These simulations were based on the screw patterns and correction techniques proposed by 2 experienced surgeons for 2 AIS cases. Additional instrumentations were assessed to compare the correction and resulting bone-screw forces associated with each type of screw. The fixed-angle, uniaxial and saddle axial screws had similar kinematic behavior and performed better than multiaxial screws in the coronal and transverse planes (8% and 30% greater simulated corrections, respectively). Uniaxial and multiaxial screws were less effective than fixed-angle and saddle axial screws in transmitting compression/distraction to the anterior spine because of their sagittal plane mobility between the screw head and shank. Only the saddle axial screws allow vertebra angle in the sagittal plane to be independently adjusted. Pedicle screws of different designs performed differently for deformity corrections or for compensating screw placement variations in different anatomic planes. For a given AIS case, screw types should be determined based on the particular instrumentation objectives, the deformity's stiffness and characteristics so as to make the best of the screw designs.